Category: Blog

Pressure vessels are essential containers used in diverse industries to store liquids or gases under varying pressures. They play a critical role in maintaining safety and operational efficiency. Understanding the different types of pressure vessels is crucial for selecting the right one for specific applications.

From distillation columns in the chemical industry to boilers in power plants and heat exchangers in HVAC systems, each type serves a unique purpose. Proper selection and maintenance of pressure vessels are vital to prevent accidents and ensure optimal performance in industrial settings.

1. What Are Pressure Vessels?

Pressure vessels are specialised containers used to store or transport substances at high pressures. They find applications across diverse industries such as oil and gas, chemical processing, food and beverage, pharmaceutical, and aerospace. Selecting the appropriate pressure vessel for a particular application is crucial for maintaining operational safety and efficiency.

Factors such as the type of substance being stored, the required pressure and temperature conditions, and regulatory compliance must be considered. Proper selection and maintenance of pressure vessels are essential to prevent accidents and ensure optimal performance in industrial operations.

2. Types of Pressure Vessels

Distillation Columns

Distillation columns are crucial in the chemical industry for separating components in a liquid mixture. They work by heating the mixture to create vapour and then cooling the vapour to create a liquid. Distillation columns are used in processes such as refining crude oil and producing chemicals.

Boilers

Boilers are essential in generating steam for heating, power generation, or other industrial processes. They are widely used in power plants and various industrial settings. Boilers are designed to withstand high pressures and temperatures to ensure the efficient generation of steam.

Heat Exchangers

Heat exchangers play a vital role in controlling temperatures and facilitating heat exchange in various industrial processes. They work by transferring heat between two or more fluids without mixing them. Heat exchangers are used in HVAC systems, refrigeration units, and chemical processing plants.

Reactors

Reactors are used to contain chemical reactions in industries such as pharmaceuticals and petrochemicals. They are designed to withstand high pressures and temperatures and provide precise control over reactions. Reactors are crucial for producing drugs, chemicals, and other products.

Storage Tanks

Storage tanks are used to store liquids or gases at different pressures and temperatures. They are widely used in industries such as oil and gas, chemical processing, and food and beverage. Storage tanks come in various sizes and designs to meet the specific storage requirements of different substances.

3. Applications Across Industries

Oil and Gas

Pressure vessels are integral in the oil and gas industry for storing and transporting crude oil, natural gas, and various petroleum products. They are used in exploration, production, and refining processes to ensure the safe handling and storage of hydrocarbons.

Chemical Processing

In the chemical industry, pressure vessels are used in various processes, including chemical reactions, distillation, and storage of chemicals. They are designed to withstand corrosive substances and high temperatures to ensure the efficient production of chemicals.

Food and Beverage

Pressure vessels play a crucial role in the food and beverage industry for processes such as pasteurisation, sterilisation, and fermentation. They are used to ensure the safety and quality of food and beverage products by controlling temperature and pressure.

Pharmaceutical

In the pharmaceutical industry, pressure vessels are used in the production of drugs, vaccines, and other medical products. They are designed to meet strict regulatory requirements and ensure the safe production of pharmaceutical products.

Aerospace

Pressure vessels are used in the aerospace industry for storing fuel, gases, and other fluids in aircraft and spacecraft. They are designed to withstand high pressures and temperatures experienced during flight and ensure the safety and reliability of aerospace vehicles.

4. Considerations for Choosing a Pressure Vessel

When selecting a pressure vessel, numerous factors must be taken into account to ensure its suitability for the intended application. Operating conditions such as pressure and temperature are critical considerations, as they dictate the vessel’s design specifications. The material used in the vessel’s construction must be compatible with the substances it will contain to prevent corrosion or contamination.

Additionally, regulatory compliance is paramount to ensure that the vessel meets all relevant standards and regulations for safety and environmental protection. Choosing the right pressure vessel is crucial for maintaining operational efficiency and preventing potential hazards. Therefore, careful consideration of these factors is essential to ensure that the selected vessel meets the specific requirements of the application and complies with all relevant regulations.

Final Thoughts

Understanding the different types of pressure vessels and their applications is crucial for ensuring safety and efficiency in industrial processes. By selecting the right pressure vessel for a specific application, industries can optimise their processes and enhance overall productivity. Pressure vessels are essential components in various industries, and their proper selection and maintenance are critical for ensuring the safe and efficient operation of industrial processes.

Choose Sherwood Engineering For Pressure Vessel Design

With over 40 years of experience in engineering design services, Sherwood Design & Engineering is committed to delivering excellence in pressure vessel design, manufacturing, and support services. Our team of qualified engineers, designers, and consultants are dedicated to meeting the unique needs of various industries, ensuring compliance with regulations, and providing innovative solutions that enhance safety and performance.

Give us a call at (02) 9437 3566 or leave an enquiry if you would like to learn more about our pressure vessel engineering design and support services.

Pressure vessels are indispensable components in a myriad of industries, serving as the backbone for the storage and transportation of liquids and gases at high pressures. Their role is pivotal in maintaining the safety and efficiency of industrial processes, spanning from oil and gas extraction to chemical manufacturing and power generation.

However, to ensure their continued reliability and performance, a rigorous regimen of regular inspection and maintenance is paramount.

This article delves into the criticality of such practices, outlining the potential risks associated with neglect, the key methodologies for inspection and maintenance, and the overarching benefits of adopting a proactive maintenance strategy.

Introduction

In the industrial landscape, pressure vessels are ubiquitous, designed to contain gases or liquids at pressures significantly diverging from the ambient. Their applications are vast, touching upon sectors like oil and gas, chemical processing, and power generation.

The diversity in their use case necessitates a deep understanding of their operation, maintenance, and safety implications.

Understanding Pressure Vessels

Constructed in a variety of shapes and sizes, pressure vessels range from small household units, such as propane tanks, to massive industrial boilers and reactors.

While steel remains the predominant material of choice due to its strength and resilience, advancements in material science have introduced alternatives like aluminium and various composite materials, offering benefits such as corrosion resistance and weight reduction.

Safety Concerns

The catastrophic failure of a pressure vessel is not a mere inconvenience but a potential disaster, with the possibility of explosions, fires, and substantial environmental harm. Such failures not only pose a direct threat to human life but can also inflict severe financial and reputational damage upon businesses.

Thus, regular inspection and maintenance emerge as non-negotiable necessities to avert these dire outcomes.

Regulatory Standards

The operation of pressure vessels is tightly governed by a complex framework of regulations and standards, designed to ensure their safe usage.

These encompass design codes, inspection protocols, and maintenance guidelines, all aimed at minimising the risk of failure and enhancing operational safety. Compliance with these standards is not optional but a legal and moral obligation for operators.

Benefits of Regular Inspection

Through diligent inspection, potential issues can be identified and remedied before escalating into significant problems. This proactive approach not only diminishes the likelihood of accidents but also contributes to the seamless and safe operation of pressure vessels, ensuring that they continue to serve their intended purpose without interruption.

Key Inspection and Maintenance Practices

Effective inspection and maintenance strategies employ a blend of visual assessments, non-destructive testing (NDT) methods like ultrasonic and radiographic testing, and corrosion prevention techniques. These practices are crucial for detecting defects, assessing structural integrity, and ensuring that vessels can withstand the stresses of their operational environments.

Case Studies

Historical incidents underscore the importance of stringent maintenance routines. By examining case studies where failure to maintain pressure vessels led to accidents, the value of regular inspections becomes starkly evident. These real-world examples serve as cautionary tales, emphasising the critical nature of maintenance in preventing similar incidents.

Cost Considerations

While it’s undeniable that inspection and maintenance entail financial outlay, the costs associated with preventive care are invariably lower than the expenses arising from emergency repairs, operational downtime, or, in the worst-case scenario, catastrophic failures. Investing in regular maintenance is both a cost-effective and prudent strategy.

Environmental Impact

The rupture or failure of a pressure vessel can have devastating effects on the environment, leading to the release of hazardous substances and contamination. Maintaining these vessels not only safeguards human life and property but also protects the environment from potential harm, aligning with broader goals of sustainability and ecological stewardship.

Final Thoughts

The imperative for regular inspection and maintenance of pressure vessels transcends mere operational efficiency. It is a fundamental aspect of ensuring safety, environmental protection, and long-term reliability.

By adhering to established best practices and regulatory standards, industries can mitigate risks, prevent accidents, and secure the longevity of their pressure vessels. Thus, a commitment to proactive maintenance programs is not just a regulatory compliance issue but a cornerstone of responsible industrial operation.

In summary, the regular inspection and maintenance of pressure vessels are indispensable for guaranteeing their safe and efficient function. Through the implementation of comprehensive maintenance regimes and strict adherence to regulatory mandates, the risk of catastrophic failures can be significantly reduced, ensuring the continued viability and safety of these critical industrial components.

Choose Sherwood Engineering For Pressure Vessel Design

With over 40 years of experience in engineering design services, Sherwood Design & Engineering is committed to delivering excellence in pressure vessel design, manufacturing, and support services. Our team of qualified engineers, designers, and consultants are dedicated to meeting the unique needs of various industries, ensuring compliance with regulations, and providing innovative solutions that enhance safety and performance.

Give us a call at (02) 9437 3566 or leave an enquiry if you would like to learn more about our pressure vessel engineering design and support services.

In the realm of industrial processes, pressure vessels play a pivotal role in containing and managing various substances under different pressure and temperature conditions. Whether you are in the chemical, petrochemical, pharmaceutical, or food processing industry, selecting the right pressure vessel is crucial for the success and safety of your operations. 

In this guide, we will walk you through the essential steps to help you make an informed decision when choosing a pressure vessel for your industrial process.

Understanding Your Process Requirements

Before diving into the world of pressure vessels, it’s essential to gain a deep understanding of your specific industrial process. This involves identifying the unique needs and challenges that your operation presents. Here are some key factors to consider:

Begin by pinpointing the primary purpose of the pressure vessel in your process. Are you storing, mixing, or reacting substances? Understanding the vessel’s role will guide your decision-making process.

The operating pressure and temperature are critical parameters that dictate the type of pressure vessel required. You must have a clear understanding of the maximum and minimum values for these factors in your process.

Consider the nature of the substances that will be stored or processed within the pressure vessel. Some materials may be corrosive, reactive, or pose health and safety risks, requiring specific design and material considerations.

Compliance with Regulations

Ensuring compliance with industry standards and regulations is non-negotiable when it comes to pressure vessels. In Australia, pressure vessel safety is governed by strict regulations to protect workers, the environment, and the public. Here’s what you need to keep in mind:

Familiarise yourself with relevant Australian and international standards that apply to pressure vessels. The AS 1210 and ASME Boiler and Pressure Vessel Code are commonly referenced standards in Australia.

Understand the legal obligations and requirements set forth by Australian authorities, such as Safe Work Australia and state-level regulators. Compliance ensures that your pressure vessel meets safety and environmental standards.

Compliance with regulations not only ensures the safety of your operations but also helps mitigate environmental impacts. It’s essential to have safety mechanisms and systems in place to prevent accidents and respond to emergencies.

Material Selection

Choosing the right material for your pressure vessel is a critical decision, as it directly impacts its performance, durability, and longevity. Factors influencing material selection include:

Consider the substances the vessel will come into contact with and their potential to corrode or react with the vessel’s material. Stainless steel, carbon steel, and specialised alloys offer varying degrees of corrosion resistance.

Evaluate the strength and durability requirements based on the operating conditions. Thicker materials may be necessary for higher pressures, while thinner materials may suffice for lower-pressure applications.

Balancing material costs with long-term benefits is essential. While some materials may be more expensive upfront, they could offer significant savings in terms of maintenance and longevity.

Design and Construction

The design and construction of your pressure vessel should align with your process requirements and safety considerations:

• Shape and Size: The shape and size of the vessel should be optimised for your specific application, considering factors like space constraints and fluid dynamics.
• Thickness Calculations: Proper thickness calculations are essential to ensure the vessel can withstand the desired pressure and temperature ranges.
• Reinforcements and Supports: Depending on the vessel’s size and shape, additional reinforcements and support structures may be necessary for stability and safety.

Decide whether to opt for off-the-shelf or custom-designed pressure vessels. Off-the-shelf options are readily available and may be suitable for standard applications. Custom-designed vessels offer greater flexibility to meet unique requirements but may involve longer lead times and higher costs.

Safety Features and Testing

Safety should be a top priority in pressure vessel selection. Incorporating safety features and rigorous testing is vital to prevent accidents and ensure reliability:

• Pressure Relief Systems: Pressure relief valves and rupture discs are essential for safeguarding against overpressure situations.
• Emergency Shutdown Systems: Implementing emergency shutdown systems can quickly isolate the vessel in case of emergencies.
• Non-Destructive Testing (NDT): Regular NDT, such as radiographic testing (RT) and ultrasonic testing (UT), helps detect defects and ensures the vessel’s integrity.

Pressure vessels should have mechanisms in place to relieve excess pressure, preventing catastrophic failures. These safety features provide peace of mind and protect personnel and equipment.

Long-Term Maintenance and Durability

The longevity of your pressure vessel depends on proper maintenance and care:

Implement routine inspection and maintenance schedules to detect and address issues early. Regular checks can identify corrosion, wear, or fatigue, allowing for timely repairs.

Corrosion and wear are common issues in pressure vessels. Implement protective coatings or linings and use corrosion-resistant materials to mitigate these problems.

Cost Analysis

A thorough cost analysis is crucial to understanding the financial implications of your pressure vessel choice:

Consider the total cost of ownership, which includes initial purchase costs, installation, maintenance, and energy efficiency. Balancing these factors will help you make a financially sound decision.

Assess the potential return on investment (ROI) associated with different vessel options. Sometimes, investing in a higher-quality vessel can yield substantial long-term savings.

Final Thoughts

In conclusion, choosing the right pressure vessel for your industrial process is a multifaceted task that requires careful consideration of process requirements, regulatory compliance, material selection, design, safety features, and cost analysis. 

By following these steps and prioritising safety and efficiency, you can make an informed decision that not only enhances your operations but also ensures the well-being of your workforce and the environment. Pressure vessels are the backbone of many industrial processes, and selecting the right one is an investment in the success and sustainability of your operations.

Choose Sherwood Engineering For Pressure Vessel Design

With over 40 years of experience in engineering design services, Sherwood Design & Engineering is committed to delivering excellence in pressure vessel design, manufacturing, and support services. Our team of qualified engineers, designers, and consultants are dedicated to meeting the unique needs of various industries, ensuring compliance with regulations, and providing innovative solutions that enhance safety and performance.

Give us a call at (02) 9437 3566 or leave an enquiry if you would like to learn more about our pressure vessel engineering design and support services.

Pressure vessels play a crucial role in a wide range of industries, but their significance is particularly pronounced in the food and beverage sector. These vessels are not only responsible for processing and preserving various food products but also ensuring the highest standards of sanitation and compliance with strict regulatory frameworks. In this article, we will delve into the vital role pressure vessels play in the food and beverage industry, focusing on their contribution to sanitation and regulatory compliance.

Pressure Vessels in Food and Beverage Processing

1). Role of Pressure Vessels in Various Processing Stages

Pressure vessels are essential components in different stages of food and beverage processing, contributing to the creation of safe and high-quality products. In processes such as cooking and sterilization, pressure vessels create the ideal conditions for eliminating harmful microorganisms and extending shelf life. During pasteurization, these vessels play a pivotal role in maintaining the product’s quality while ensuring safety. Additionally, in fermentation processes like brewing, pressure vessels create controlled environments that foster the growth of beneficial microorganisms.

2). Contribution to Quality and Safety of Food Products

The utilization of pressure vessels in food and beverage processing goes beyond basic functionality. Their presence directly impacts the quality and safety of the final products. The precise control of pressure and temperature within these vessels not only enhances taste, texture, and flavor but also ensures that products are free from pathogens and contaminants that can jeopardize consumer health.

H2: Sanitary Design of Pressure Vessels

1). Hygienic Design Principles

Sanitary design is of paramount importance when it comes to pressure vessels used in the food and beverage industry. The construction of pressure vessels must adhere to hygienic design principles that prioritize food safety. These principles encompass the use of smooth surfaces and crevice-free construction to prevent the accumulation of debris and bacteria. Additionally, pressure vessels must be designed for easy cleanability, minimizing the risk of microbial growth and cross-contamination.

2). Preventing Bacterial Growth and Cross-Contamination

Effective sanitation involves preventing bacterial growth and cross-contamination throughout the food processing cycle. Pressure vessels with hygienic design features minimize the likelihood of bacterial harborage points, ensuring that the processing environment remains uncontaminated. The absence of hidden areas and the use of materials resistant to corrosion and microbial attachment further contribute to preventing the spread of pathogens.

3). Ensuring Compliance with Food Safety Regulations

Regulatory bodies worldwide impose stringent requirements on the design and operation of pressure vessels used in the food and beverage industry. These regulations, such as those set by the U.S. Food and Drug Administration (FDA) or European Union standards for food contact materials, mandate that pressure vessels maintain a hygienic design to prevent contamination. Adherence to these regulations is not only essential for consumer safety but also to avoid legal consequences that can arise from non-compliance.

Regulatory Framework for Pressure Vessels in Food Industry

1). Food Safety Regulations and Standards

The food industry operates under a complex web of regulations to safeguard consumer health. Pressure vessels used in food processing are subject to specific regulations that address their design, construction, and operation. For instance, the FDA’s Code of Federal Regulations Title 21 outlines requirements for materials, finishes, and construction of equipment that comes in contact with food. Similarly, the EU’s Regulation (EC) No 1935/2004 sets standards for materials intended for food contact.

2). Documentation and Certification Requirements

Pressure vessel manufacturers must provide comprehensive documentation and certifications to demonstrate compliance with relevant regulations. This documentation includes material certificates, design calculations, and test reports. Certifications from authorized bodies further validate that pressure

 vessels meet the necessary standards, ensuring their suitability for food processing.

3). Consequences of Non-Compliance

Non-compliance with food safety regulations can have severe repercussions. Contaminated products can lead to foodborne illnesses, product recalls, and damage to a brand’s reputation. Legal consequences, fines, and sanctions can also result from failing to adhere to the established standards, underscoring the critical importance of compliance in the food and beverage industry.

Cleaning and Maintenance of Food Grade Pressure Vessels

1). Cleaning Procedures to Maintain Hygiene

Maintaining cleanliness and hygiene within pressure vessels is essential to prevent the growth of harmful microorganisms and ensure the integrity of food products. Clean-In-Place (CIP) systems are widely used for automated cleaning of equipment, including pressure vessels. These systems use a combination of chemicals, heat, and mechanical action to remove residues and contaminants. Sterilize-In-Place (SIP) processes are also employed to sanitse pressure vessels before and after processing, ensuring optimal hygiene levels.

2). Preventing Cross-Contamination During Cleaning

Efforts to maintain sanitation must include measures to prevent cross-contamination during the cleaning process. Thorough rinsing and the removal of cleaning agents are essential to prevent any residues from compromising the quality and safety of subsequent batches. Implementing effective cleaning validation protocols ensures that pressure vessels are properly cleaned and free from potential contaminants.

3). Regular Inspection and Maintenance Schedules

Routine inspection and maintenance of food grade pressure vessels are essential to identify and address potential issues before they escalate into critical problems. Regular inspection schedules enable the detection of wear and tear, corrosion, and other signs of deterioration. Prompt maintenance and repairs not only extend the lifespan of pressure vessels but also contribute to the overall safety and quality of food processing operations.

Challenges in Pressure Vessel Sanitation

1). High-Temperature Processes and Material Considerations

The food and beverage industry often involves high-temperature processes that can challenge the materials used in pressure vessels. Ensuring that materials are compatible with the processing conditions, resistant to corrosion, and capable of withstanding thermal stress is crucial to maintaining vessel integrity and preventing contamination.

2). Ensuring Effective Cleaning of Complex Vessel Shapes

Pressure vessels come in various shapes and sizes, some of which may have intricate geometries that pose challenges for effective cleaning. Dead spaces, corners, and narrow passages can become potential areas for bacterial growth and residue accumulation. Overcoming these challenges requires innovative design approaches and cleaning techniques.

3). Addressing Fouling and Product Residue

Fouling and product residue buildup can compromise the cleanliness of pressure vessels over time. Food products with high sugar or protein content are particularly prone to fouling. Implementing specialized cleaning procedures and adopting materials with anti-fouling properties can mitigate this issue and ensure consistent sanitation.

Innovations in Pressure Vessel Design for Sanitation

1). Self-Cleaning Mechanisms

Advancements in pressure vessel design have led to the incorporation of self-cleaning mechanisms. These mechanisms utilize fluid dynamics and specialized internal surfaces to facilitate the removal of residues and contaminants during processing. Such innovations contribute to more efficient and thorough cleaning processes.

2). Improved Sealing and Gasket Materials

Effective sealing is vital to prevent contamination and maintain pressure vessel integrity. Innovations in sealing and gasket materials have resulted in enhanced performance, ensuring a reliable barrier between the processing environment and external contaminants.

3). Integration of IoT for Real-Time Monitoring

The integration of Internet of Things (IoT) technology into pressure vessel design allows real-time monitoring of critical parameters such as temperature, pressure, and cleanliness. This connectivity enables operators to promptly detect deviations and implement corrective actions, ensuring consistent sanitation and compliance.

Case Studies: Successful Implementation of Sanitary Pressure Vessels

1). Dairy Industry: Ensuring the Safety of Milk Products

In the dairy industry, pressure vessels are utilized for processes such as pasteurization and sterilization to ensure the safety of milk and dairy products. The strict adherence to sanitary design principles and compliance with regulations guarantees that these products reach consumers in optimal condition.

2). Brewing Industry: Maintaining Quality in Beer Production

Pressure vessels play a vital role in the brewing industry, particularly during fermentation and carbonation processes. The use of sanitary vessels prevents contamination and contributes to the production of high-quality beer that meets consumer expectations.

3). Sauces and Condiments: Hygienic Processing of Food Additives

Pressure vessels are essential in the processing of sauces and condiments, where additives and flavorings are introduced. Sanitary design ensures that these additives are incorporated safely and hygienically into the final products.

Final Thoughts

Pressure vessels have become indispensable tools in the food and beverage industry, powering processes that ensure the safety, quality, and taste of products consumers enjoy. The focus on sanitation and compliance is not only a regulatory requirement but a moral obligation to protect public health. 

By adhering to strict design principles, following food safety regulations, implementing effective cleaning protocols, and embracing innovative design concepts, the food and beverage industry can continue to provide consumers with products that are not only delicious but also safe to consume.

Pressure vessels are critical components in various industries, including petrochemical, pharmaceutical, and manufacturing. These vessels are designed to store, contain, or transport fluids or gases under high pressure. To ensure the safety and performance of pressure vessels, several key design considerations must be taken into account.

In this article, we will explore these considerations, focusing on materials, thickness calculations, safety factors, welding techniques, non-destructive testing (NDT), compliance with safety standards, and real-world case studies of successful designs.

Material Selection

The choice of materials for constructing pressure vessels is of paramount importance. Different materials offer varying degrees of strength, durability, and corrosion resistance. The selected material should not only withstand the operating conditions but also be compatible with the stored or transported substances.

Pressure vessels can be constructed from a range of materials, with the most common being stainless steel, carbon steel, aluminium, and composite materials. Stainless steel is often preferred for its corrosion resistance, while carbon steel is chosen for its cost-effectiveness.

Aluminium is used when weight is a critical factor, and composite materials offer a combination of strength and lightweight properties.

Several factors influence the choice of material for a pressure vessel:

• Operating Temperature and Pressure: Materials must be capable of withstanding the temperature and pressure conditions within the vessel.
• Corrosion Resistance: The nature of the stored substances and the environment in which the vessel operates determines the level of corrosion resistance required.
• Cost Considerations: Material costs, fabrication costs, and maintenance expenses play a role in material selection.

Thickness Calculations

Determining the appropriate thickness of pressure vessel walls is crucial for ensuring structural integrity and safety. Inadequate thickness can result in catastrophic failures, while excessive thickness can lead to unnecessary weight and costs.

The ASME Boiler and Pressure Vessel Code (ASME BPVC) is a set of standards that provide guidelines for the design, fabrication, inspection, and testing of pressure vessels. It is widely recognised and adopted in the industry, serving as a benchmark for ensuring safety and quality.

Various design codes, such as ASME Section VIII, Div. 1, play a significant role in thickness calculations. These codes outline specific formulas and methods for determining thickness based on factors like internal pressure, external pressure, design temperature, and corrosion allowance.

Factors Affecting Thickness Calculations:

• Internal Pressure: The pressure inside the vessel is a critical factor, as it directly affects the required thickness.
• External Pressure: External factors, such as wind or hydrostatic pressure, can also influence thickness calculations.
• Design Temperature: Extreme temperatures can impact material properties and, consequently, thickness requirements.
• Corrosion Allowance: Including an allowance for potential corrosion ensures the vessel’s long-term integrity.

Safety Factors and Margin of Safety

Safety factors are applied to the calculated thickness to provide a margin of safety. These factors account for uncertainties in material properties, fabrication processes, and operating conditions. They ensure that pressure vessels can withstand unexpected stresses and loads.

The margin of safety is the difference between the vessel’s actual strength and the anticipated stresses it will encounter during operation. It is expressed as a ratio, with values greater than 1 indicating a safe design.

Designing pressure vessels with safety factors that exceed minimum requirements is essential. In critical applications, exceeding minimum standards can prevent catastrophic failures and ensure the protection of human lives and the environment.

Case studies of pressure vessel failures due to insufficient safety margins highlight the importance of this aspect of design. Incidents resulting in injuries, environmental damage, and financial losses underscore the need for robust safety factors.

Welding and Joining Techniques

Welding plays a central role in joining the components of pressure vessels. Proper welding techniques are essential to ensure leak-tight and structurally sound vessels.

Types of Welding Processes Used

Pressure vessel fabrication employs various welding processes, including:

• TIG Welding (Tungsten Inert Gas): Known for precision and cleanliness, TIG welding is often used in high-purity applications.
• MIG Welding (Metal Inert Gas): MIG welding offers speed and efficiency, making it suitable for many pressure vessel applications.
• SAW Welding (Submerged Arc Welding): SAW welding is ideal for welding thick sections and large vessels.

Welding Quality Control and Inspection

Quality control measures, including weld inspection, are vital to detect defects and ensure the integrity of weld joints. Radiographic testing, ultrasonic testing, and visual inspection are common methods used to assess weld quality.

Importance of Proper Joints and Weld Testing

Pressure vessel joints must be designed and executed with precision. Any flaws or defects in welds can compromise the vessel’s safety and performance. Rigorous weld testing protocols are essential to verify weld quality.

Non-Destructive Testing (NDT)

Non-destructive testing (NDT) methods are employed to assess the integrity of pressure vessels without causing damage. Common NDT methods include radiographic testing (RT), ultrasonic testing (UT), magnetic particle testing (MT), and liquid penetrant testing (PT).

NDT allows inspectors to detect internal and external flaws, cracks, or defects in pressure vessel materials or welds. This helps identify potential weaknesses before they lead to failures.

Regulatory bodies often mandate specific NDT procedures for pressure vessel inspection. Compliance with these requirements is essential to meet safety standards and ensure the reliability of vessels.

Compliance with Safety Standards

Safety standards and codes, such as ASME BPVC, are established to promote uniformity and safety in pressure vessel design, fabrication, and operation. Adhering to these standards is crucial for ensuring compliance and safety.

ASME BPVC is a globally recognised code for pressure vessel design and manufacturing. Additionally, other codes and standards may apply, depending on the industry and location.

Manufacturers and operators must ensure that pressure vessels meet both national and international safety regulations. Compliance demonstrates a commitment to safety and reduces the risk of accidents.

Final Thoughts

Pressure vessel design is a complex and critical aspect of many industries. Material selection, thickness calculations, safety factors, welding techniques, non-destructive testing, and compliance with safety standards are all essential considerations in ensuring the safety and reliability of these vessels.

With over 40 years of experience in engineering design services, Sherwood Design & Engineering is committed to delivering excellence in pressure vessel design, manufacturing, and support services.

Our team of qualified engineers, designers, and consultants are dedicated to meeting the unique needs of various industries, ensuring compliance with regulations, and providing innovative solutions that enhance safety and performance.

Give us a call at (02) 9437 3566 or leave an enquiry if you would like to learn more about our pressure vessel engineering design and support services.

Pressure vessels are critical components used in various industries, including oil and gas, chemical, aerospace, and energy, among others. These vessels are designed to hold gasses or liquids at pressures significantly higher than the ambient pressure. 

However, pressure vessel failures can lead to disastrous consequences, including leaks, ruptures, fires, and explosions, posing serious risks to human safety and the environment. 

This article delves into the common causes of pressure vessel failures and explores effective prevention techniques to ensure safe and reliable operations in Australia and beyond.

Common Causes of Pressure Vessel Failures

Pressure vessels can fail instantly due to various factors. Buckling occurs when the vessel’s walls deform and buckle under the applied loads, leading to a loss of structural integrity. 

Overload, on the other hand, occurs when the vessel is subjected to pressures beyond its designed capacity, resulting in catastrophic failure. Fast fracture refers to sudden and complete vessel rupture due to excessive stress concentrations or material defects.

Long-term failures occur over the vessel’s service life and are often insidious in nature. Fatigue failure arises from repeated loading and unloading cycles, causing cracks to propagate and eventually lead to vessel failure. Corrosion, a common issue in aggressive environments, weakens the vessel walls and compromises their integrity. 

Creep is the gradual deformation of materials under constant stress and elevated temperatures. Stress corrosion cracking occurs when a combination of tensile stress and corrosion leads to crack propagation. Hydrogen embrittlement, caused by the ingress of hydrogen into the metal structure, reduces the vessel’s ductility and increases the risk of failure.

Examining real-world case studies of pressure vessel failures provides valuable insights into the potential risks and consequences. Notable examples, such as industrial accidents or transport incidents, highlight the importance of implementing preventive measures and ensuring compliance with safety regulations.

Preventive Measures During Design and Fabrication

1). Compliance with Recognized Codes and Standards

Adhering to established Codes and Standards is crucial in pressure vessel design and fabrication. These guidelines provide detailed requirements for material selection, fabrication processes, testing, and inspection. 

Post-weld heat-treatment and proof testing are often mandatory to ensure the vessel’s structural integrity. Qualification of welders and welding procedures is critical for producing high-quality welds that can withstand pressure and mechanical loads.

2). Stress Relief of Thick Sections

Stress relief involves applying heat to reduce residual stresses in thick vessel sections. This process enhances the vessel’s stability, reduces the risk of stress-induced failures, and ensures uniform material properties throughout the structure.

3). Minimisation of Defects During Fabrication

Qualified welders and inspection techniques play a vital role in minimizing defects during fabrication. Defects such as weld discontinuities, porosity, or inclusions can significantly weaken the vessel and make it susceptible to failure.

4). The Significance of Proof Testing

Proof testing is a traditional method of verifying the vessel’s safety by pressurizing it beyond its maximum service stress. If the vessel successfully withstands this test without failure, it provides confidence in its ability to perform safely during normal operation.

 Engineering Critical Assessment (ECA)

Engineering Critical Assessment (ECA) evaluates the safety of pressure vessels by analyzing the effects of cracks or flaws on their structural integrity. Utilizing fracture mechanics principles, ECA assesses whether given flaws can lead to brittle fracture, fatigue failure, creep, or plastic collapse under specific loading conditions.

ECA is applied at various stages of a pressure vessel’s life cycle. During the design phase, it aids in selecting appropriate welding procedures and inspection techniques. During fabrication, ECA assesses the significance of known defects that may not meet fabrication Codes. In operation, ECA assists in evaluating flaws discovered during service, making decisions on whether they can safely remain, require repair, or necessitate down-rating of operating conditions.

In situations where standard ECA cannot guarantee vessel safety, more advanced techniques such as probabilistic analysis, crack arrest, or leak before break may be considered. These approaches provide a comprehensive understanding of the vessel’s performance and potential failure modes.

Fatigue Improvement Techniques

To prevent fatigue failure, pressure vessel components can be designed and analyzed using fatigue design methods. ECA can also be employed for flaws identified during service, aiding in fatigue life assessment and determining appropriate measures to avoid crack growth.

Fatigue life can be improved by removing tiny non-metallic intrusions from weld toes through grinding and inducing local compression by peening. These techniques minimize stress concentrations and enhance the vessel’s fatigue resistance.

The Role of Non-Destructive Testing (NDT)

Non-Destructive Testing (NDT) is crucial for the early detection of flaws or defects in pressure vessels. Common NDT methods include Ultrasonic Testing (UT) and Magnetic Particle Inspection (MPI) for identifying surface and subsurface cracks, Radiographic Testing (RT) for internal flaw detection, and Liquid Penetrant Testing (PT) for identifying surface discontinuities.

Accurate and reliable NDT requires skilled personnel and well-maintained equipment. Proper training and certification of NDT personnel ensure proficiency in conducting inspections and interpreting test results.

Ongoing Maintenance and Monitoring

1). Periodic Inspection Schedules

Periodic inspections are essential to identify potential risks and assess the vessel’s condition over time. Regular inspections can detect emerging issues and help prevent failures.

2). Ensuring Proper Operation Conditions and Environmental Control

Adhering to recommended operating conditions and implementing proper environmental control measures can prevent damage to the vessel due to environmental factors.

3). Maintenance and Repair Options Based on ECA Outcomes

If flaws or defects are detected during inspections, ECA outcomes can guide decisions on whether to repair the vessel, replace components, or implement modifications to ensure safety and compliance with Codes and Standards.

4). Learning from Previous Failures

Analyzing past failures and incidents can provide valuable lessons and insights into improving pressure vessel design, fabrication, and maintenance practices.

Collaborative Efforts and Industry Regulations

Industry associations play a significant role in setting safety standards and best practices. Collaborative efforts among manufacturers, inspectors, and end-users contribute to continuous improvement and ensure adherence to safety guidelines.

Strict compliance with pressure vessel safety regulations, such as those enforced by Safe Work Australia, is essential to ensure the highest standards of safety and minimize the risk of failures.

Final Thoughts

Pressure vessel failures can have devastating consequences, endangering human lives, and causing extensive damage to the environment and property. Understanding the common causes of failures and implementing preventive techniques is crucial in ensuring the safe operation of pressure vessels across various industries. 

By complying with recognized Codes and Standards, performing Engineering Critical Assessments, utilizing advanced fatigue improvement techniques, conducting regular NDT inspections, and fostering collaboration within the industry, we can proactively prevent pressure vessel failures and safeguard the well-being of workers and communities in Australia and beyond. A commitment to continuous improvement and adherence to safety regulations will pave the way for a safer and more reliable future in pressure vessel operations.

Choose Sherwood Engineering For Pressure Vessel Design

With over 40 years of experience in engineering design services, Sherwood Design & Engineering is committed to delivering excellence in pressure vessel design, manufacturing, and support services. Our team of qualified engineers, designers, and consultants are dedicated to meeting the unique needs of various industries, ensuring compliance with regulations, and providing innovative solutions that enhance safety and performance.

Give us a call at (02) 9437 3566 or leave an enquiry if you would like to learn more about our pressure vessel engineering design and support services.

In the highly demanding field of pressure vessel fabrication and repair, cost-effective solutions are of paramount importance. As industries continue to strive for operational efficiency and cost savings, pressure vessel manufacturers and repair specialists are seeking innovative approaches to optimise their processes.

This article explores various strategies and techniques that enable cost-effective solutions in pressure vessel fabrication and repair, addressing the need for efficient design and engineering, material selection and optimisation, streamlined fabrication processes, innovative repair techniques, cost analysis, and optimisation.

Efficient Design and Engineering

To achieve cost-effective solutions, pressure vessel manufacturers and designers are leveraging advanced computer-aided design (CAD) software to optimise designs. Finite element analysis (FEA) is employed to simulate stress and strain patterns, ensuring the structural integrity of pressure vessels.

Computational fluid dynamics (CFD) is utilised to analyse fluid flow characteristics within vessels, enabling efficient designs that minimise pressure losses. By leveraging these powerful tools, manufacturers can reduce design iterations, optimise performance, and eliminate costly trial-and-error approaches.

Innovative design techniques are also being implemented to create lightweight yet robust pressure vessels. Topology optimization, a cutting-edge method, is employed to achieve material savings by strategically distributing structural elements.

By identifying non-critical areas that can be minimised or eliminated, manufacturers can reduce both material costs and vessel weight. Additionally, integrated design and fabrication considerations are incorporated from the outset to minimise costs associated with manufacturing complexities.

Material Selection and Optimization

Selecting the appropriate materials is crucial for cost-effective pressure vessel fabrication. High-strength alloys with improved strength-to-weight ratios are preferred to maximise performance while reducing material usage. Advanced composites, such as carbon fibre-reinforced polymers, offer corrosion resistance and substantial weight reduction, resulting in lower transportation and installation costs.

Optimising material usage through efficient nesting and cutting techniques further contributes to cost-effectiveness. Computer numerical control (CNC) machining, driven by precise CAD models, enables manufacturers to minimise waste and achieve high material utilisation rates. With strategic nesting algorithms, smaller offcuts are repurposed, ensuring that minimal material is wasted during the fabrication process.

Streamlined Fabrication Processes

Automation and robotics are revolutionising pressure vessel fabrication, leading to enhanced productivity and reduced labour costs. Robotic welding and fabrication techniques ensure consistent quality, precision, and efficiency, eliminating variations that can result from human error.

Automated material handling and assembly processes streamline production, reducing cycle times and labour costs while maintaining high standards of quality control.

Implementing lean manufacturing principles is also instrumental in achieving cost-effective fabrication processes. Just-in-time (JIT) inventory management minimises storage costs by ensuring the timely delivery of components and materials. Value stream mapping helps identify and eliminate non-value-added processes, optimising production flow and reducing overall manufacturing time. By implementing these techniques, manufacturers can eliminate waste, minimise lead times, and improve cost efficiency.

Innovative Repair Techniques

Pressure vessel repair is a critical aspect of maintaining their lifespan and ensuring safety. Non-destructive testing (NDT) methods play a vital role in the accurate assessment and inspection of vessel integrity.

Techniques such as ultrasonic testing (UT) enable flaw detection and precise measurement of wall thickness, while magnetic particle inspection (MPI) detects surface cracks that may compromise vessel integrity. By using NDT methods, repair specialists can pinpoint areas that require attention, reducing repair costs and mitigating potential risks.

Advanced repair technologies are also employed to extend the lifespan of pressure vessels and minimise downtime. Cold spray coating, a technique in which a protective layer is sprayed onto the vessel’s surface, provides corrosion resistance and restores damaged areas.

Composite patching and repair methods, utilising high-strength composites, enable localised repairs while maintaining vessel integrity. These innovative techniques offer cost-effective solutions by targeting specific areas of repair, reducing the need for costly replacements or extensive vessel refurbishments.

Cost Analysis and Optimization

To ensure cost-effective pressure vessel fabrication and repair, manufacturers employ rigorous cost analysis and optimization techniques. Tracking material and labour costs throughout the fabrication process enables accurate estimation and control of expenses. By continuously evaluating and optimising production efficiency and resource utilisation, manufacturers can identify areas for improvement and cost reduction.

Collaboration with suppliers and contractors is also essential for cost-effective procurement and services. Negotiating favourable pricing and contracts with material suppliers and service providers helps reduce overall project costs. Leveraging strategic partnerships allows manufacturers to benefit from shared expertise, enabling efficient project execution and reduced costs.

Final Thoughts

Cost-effective solutions in pressure vessel fabrication and repair are crucial for industries seeking operational efficiency and cost savings. By embracing efficient design and engineering practices, optimising material selection and utilisation, streamlining fabrication processes, utilising innovative repair techniques, and implementing cost analysis and optimisation strategies, manufacturers and repair specialists can achieve substantial cost savings while maintaining high-quality standards.

These cost-effective approaches will continue to drive advancements in the pressure vessel industry, ensuring safe and reliable operations for various sectors while maximising financial efficiency.

With over 40 years of experience in engineering design services, Sherwood Design & Engineering is committed to delivering excellence in pressure vessel design, manufacturing, and support services. Our team of qualified engineers, designers, and consultants are dedicated to meeting the unique needs of various industries, ensuring compliance with regulations, and providing innovative solutions that enhance safety and performance.

Give us a call at (02) 9437 3566 or leave an enquiry if you would like to learn more about our pressure vessel engineering design and support services.

Many different industries, including oil and gas, chemical processing, and food and beverage production, use pressure vessels. They are essential to many industrial processes and are made to hold liquids and gases under high pressure. Pressure vessel manufacturers are constantly looking into new materials and designs to enhance the safety, effectiveness, and performance of these vessels as technology develops. 

In this blog post, we’ll look at the latest developments in materials and design that are reshaping the pressure vessel industry as well as the technology’s potential for the future.

Advancements In Pressure Vessel Materials

Pressure vessels have traditionally been constructed using materials like steel and other metals due to their strength and durability. However, recent advancements in materials science have opened up new possibilities for enhancing pressure vessel performance. Here are some key advancements in pressure vessel materials:

• Lightweight and High-Strength Materials: Manufacturers are exploring the use of advanced alloys and composite materials that offer high strength-to-weight ratios. These materials not only reduce the weight of pressure vessels but also improve their structural integrity.
• Composite Materials and Their Benefits: Fiberglass-reinforced composites and carbon fiber composites are gaining popularity in pressure vessel construction. These materials offer excellent corrosion resistance, high strength, and the ability to withstand extreme temperatures. Additionally, they are lighter than traditional materials, making them ideal for applications where weight reduction is crucial.
• Corrosion-Resistant Materials for Extended Lifespan: Corrosion is a common concern for pressure vessels, especially in industries dealing with aggressive chemicals or marine environments. The development of corrosion-resistant materials, such as stainless steel alloys and specialised coatings, helps increase the lifespan of pressure vessels while maintaining their structural integrity.

Innovative Pressure Vessel Designs

Advancements in pressure vessel design have focused on improving safety, efficiency, and versatility. Here are some innovative designs that are shaping the future of pressure vessels:

• Modular and Scalable Designs for Flexibility: Modular pressure vessel designs allow for easy assembly and disassembly, enabling quick modifications and repairs. They also provide the flexibility to scale up or down based on operational requirements. This modular approach improves efficiency, reduces downtime, and optimises maintenance processes.
• Integration of Sensors and Monitoring Systems: Smart pressure vessels equipped with sensors and monitoring systems enable real-time data collection and analysis. These systems monitor parameters like temperature, pressure, and structural integrity, providing early warnings of potential issues. Such integration enhances safety, enables predictive maintenance, and optimises performance.
• Improved Insulation and Energy Efficiency: Energy efficiency is a key focus in pressure vessel design. Innovative insulation materials and techniques help minimise heat transfer and reduce energy loss. By optimising insulation, pressure vessels can maintain stable internal temperatures, reducing energy consumption and operating costs.

Enhancing Safety And Performance

Ensuring the safety and optimal performance of pressure vessels is of paramount importance in various industries. Here are some notable advancements aimed at enhancing safety and performance:

• Non-Destructive Testing Methods for Early Detection of Defects: Non-destructive testing techniques, such as ultrasonic testing, radiography, and magnetic particle inspection, have evolved to become more accurate and efficient. These methods allow for the detection of potential defects or weaknesses in pressure vessel components without causing any damage. Early detection helps prevent catastrophic failures and ensures the integrity of the vessel.
• Advanced Simulation and Modelling Techniques: With the aid of advanced computer simulation and modelling tools, engineers can predict the behavior of pressure vessels under different operating conditions. Finite element analysis (FEA) and computational fluid dynamics (CFD) simulations enable accurate stress analysis, thermal analysis, and fluid flow predictions. These simulations aid in optimising designs, improving structural integrity, and enhancing overall performance.
• Risk Assessment and Safety Regulations: Safety regulations and industry standards play a crucial role in ensuring the safe operation of pressure vessels. Continued advancements in risk assessment methodologies allow for comprehensive evaluations of potential hazards and risks associated with pressure vessels. Implementing robust safety protocols, such as regular inspections, maintenance schedules, and training programs, helps mitigate risks and maintain high safety standards.

Applications In Various Industries

Pressure vessels find extensive applications across various industries, each with unique requirements. Here are some notable applications:

• Oil and Gas Sector Advancements: The oil and gas industry heavily relies on pressure vessels for activities such as refining, storage, and transportation of petroleum products. Advancements in pressure vessel technology have led to the development of specialised vessels capable of handling high pressures and corrosive substances, contributing to safer and more efficient operations in the sector.
• Chemical Processing Industry Innovations: Chemical processing plants utilise pressure vessels in numerous processes, including chemical reactions, distillation, and purification. Custom-designed vessels with specific materials and corrosion-resistant coatings are employed to handle aggressive chemicals and ensure optimal performance, enabling the chemical industry to meet strict quality and safety standards.
• Emerging Trends in Food and Beverage Applications: Pressure vessels play a vital role in the food and beverage industry, particularly in areas such as food processing, brewing, and beverage production. These vessels help maintain controlled environments, ensure product quality and safety, and facilitate efficient processing and storage of perishable goods.

Challenges And Future Outlook

Despite the advancements in pressure vessel technology, there are still challenges to overcome and exciting opportunities on the horizon. Here are some key challenges and the future outlook for pressure vessels:

• Regulatory Compliance and Standards: Adhering to stringent safety regulations and industry standards remains a challenge for pressure vessel manufacturers and operators. However, these regulations are crucial in ensuring the safety of personnel and the environment. The future will see a continued emphasis on compliance and the development of more robust standards to address emerging technologies and evolving industry needs.
• Integration with Digital Technologies and Automation: The integration of pressure vessels with digital technologies, such as the Internet of Things (IoT) and artificial intelligence (AI), opens up new possibilities for enhanced monitoring, predictive maintenance, and process optimisation. Automation, remote monitoring, and data-driven insights will play a significant role in improving the efficiency, safety, and performance of pressure vessels in the future.
• Predictions for the Future of Pressure Vessel Technology: Looking ahead, pressure vessel technology is expected to advance in several areas. This includes the development of new materials with improved strength, corrosion resistance, and weight reduction. Additionally, designs will become more modular, scalable, and adaptable to changing operational needs. Integration of advanced sensors, real-time monitoring systems, and predictive analytics will become more prevalent, enabling proactive maintenance and minimising downtime.

Final Thoughts

The future of pressure vessel technology holds great promise. Advancements in materials, innovative designs, enhanced safety measures, and digital integration are revolutionising the industry. As the demand for safer and more efficient pressure vessels continues to grow, Sherwood Design & Engineering is at the forefront of providing cutting-edge solutions.

With over 40 years of experience in engineering design services, Sherwood Design & Engineering is committed to delivering excellence in pressure vessel design, manufacturing, and support services. Our team of qualified engineers, designers, and consultants are dedicated to meeting the unique needs of various industries, ensuring compliance with regulations, and providing innovative solutions that enhance safety and performance.

Give us a call at (02) 9437 3566 or leave an enquiry if you would like to learn more about our pressure vessel engineering design and support services.

A pressure vessel is a type of container that can maintain a pressure above or below the surrounding atmosphere. Pressure vessels are indispensable in many fields because they make it possible to transport and store pressurised gases and liquids. Many industrial processes rely on the vessels, which are crucial to their success.

In today’s blog, we’ll take a comprehensive look at the basics of pressure vessels including how they work, their applications, design and fabrication, inspection and maintenance, as well as safety and regulations. 

How Pressure Vessels Work

Pressure vessels operate by containing pressurised gases or liquids within a strong vessel. Following is a quick guide on how pressure vessels work:

1). Fundamentals of pressure

A fluid’s pressure is the force exerted per unit area. Fluids include gases and liquids. The pressure in a pressure vessel stays inside the vessel, hence the walls of the vessel need to be sturdy enough to withstand the pressure’s force. The standard pressure measurement is in pounds per square inch. (PSI).

2). Operating principles of pressure vessels

To function, pressure vessels must have the forces acting on their walls in equilibrium. The vessel’s walls must be sturdy enough to withstand the pressure created when a pressurised gas or liquid is placed within. Pressure resistance is directly proportional to the thickness of the vessel walls and the strength of the material used to build the vessel.

3). Pressure vessel failure modes

Corrosion, fatigue, and excessive pressure are only a few of the causes of pressure vessel collapse. The metal of the vessel walls corrodes when it reacts chemically with the contents of the vessel, a process known as corrosion. Repeated loading and unloading cause fatigue failure, which can result in cracks and eventual failure of the vessel. When the internal pressure of a vessel exceeds its safe operating range, overpressure occurs and can cause the vessel to burst or explode.

Applications of Pressure Vessels

Pressure vessels are essential components of many industries, including oil and gas, aerospace, and energy. Understanding the applications of pressure vessels is crucial for ensuring their safe and effective use in various industries.

1). Oil and gas industry

The oil and gas industry relies heavily on pressure vessels for the storage and transportation of gases and liquids. Pressure vessels are used for a range of functions, such as storing crude oil, transporting natural gas, and processing petroleum products.

2). Aerospace industry

Storage of rocket fuel and propellants are just two examples of the many uses for pressure vessels in the aerospace sector. Aircraft frequently make use of pressure vessels to hold hydraulic fluid, oxygen, and other gases.

3). Energy industry

Storage of natural gas and hydrogen are only two examples of the many uses for pressure vessels in the energy sector. The coolant and control rods in nuclear reactors are often stored in pressure vessels.

Design and Fabrication of Pressure Vessels

The design and fabrication of pressure vessels require careful consideration of various factors, such as materials selection, welding techniques, and intended application. Let’s take a look at some of these factors below:

Design considerations

The pressure and temperature of the contents, the vessel’s intended function, and the materials used in its construction are only few of the considerations that must go into the design of a pressure vessel. Size and shape determination, material and welding technique selection, and pressure resistance testing are all important design concerns.

Materials selection

Pressure vessel safety and efficiency depend heavily on the materials used in their construction. The materials used in the vessel must be strong enough to endure the contents’ pressure, temperature, and corrosion. Carbon steel, stainless steel, and high-strength alloys are frequently utilised in the building of pressure vessels. Carbon fibre and other composites are employed in a variety of contexts.

Fabrication techniques

In order to ensure the safe operation of pressure vessels, they are fitted with a wide range of safety features and equipment. Some common pieces of safety hardware are pressure relief valves, rupture disks, and pressure gauges. All possible pressure vessel failures and malfunctions can be detected and counteracted by these safety measures and apparatus.

Forging, rolling, and welding are just a few of the many methods available for creating pressure vessels. Skilled welders are essential for the fabrication of pressure vessels because welding is one of the most popular methods. The use of additive manufacturing processes like 3D printing for the creation of pressure vessels is also being researched.

Safety and Regulations for Pressure Vessels

When operating a pressure vessel, safety must always come first. The loss of life or serious harm is possible if a pressure vessel fails or malfunctions. Accidents can be avoided and pressure vessels can maintain their integrity if they are designed, manufactured, tested, and operated in accordance with industry standards and safety criteria.

There are many sets of rules and guidelines that must be followed when working with pressure vessels. These rules and guidelines are in place to guarantee that pressure vessels are safe to use and constructed to last. The American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code and the European Pressure Equipment Directive are two examples of such regulations and standards for pressure vessels. (PED).

Final Thoughts

The safe and efficient operation of pressure vessels is crucial for protecting the reliability of industrial processes. It is crucial to have a firm grasp on the fundamentals of pressure vessels in order to guarantee their safe and effective use across a wide range of industries. New developments in the field of pressure vessel technology promise a promising future, and it will be fascinating to observe how they influence the market. 

Sherwood Design & Engineering has a long and successful history of offering premium pressure vessel solutions. Numerous businesses all over the world have come to rely on us as a partner because of our proficiency in pressure vessel design, fabrication, and testing as well as our dedication to customer satisfaction and safety. 

Give us a call at (02) 9437 3566 or leave an enquiry if you would like to learn more about our pressure vessel engineering design and support services.

When storing or transporting gases or liquids under high pressure, and typically high temperatures, pressure vessels are the vessels of choice. Aerospace, automotive, energy, oil and gas, and other sectors all make use of these vessels.

Improvements in materials, design, and production methods have allowed for substantial development in the field of pressure vessel technology over time. Steel, aluminium, and composites are all used in modern pressure vessels, and cutting-edge design and production methods like finite element analysis and automated welding are standard.

Importance Of Pressure Vessels In Various Industries

Industries rely heavily on pressure vessels, which are used to store and transport pressurised gases and liquids. For instance, compressed natural gas is stored in pressure vessels in the automotive sector, while natural gas and hydrogen are stored in pressure vessels in the energy business. Pressure vessels serve many purposes in the oil and gas sector, including warehousing, transporting, and processing various oil and gas products. In a nutshell, many different businesses cannot function without the use of pressure vessels.

Advancements In Pressure Vessel Materials

Following are some of the more recent advancements in pressure vessel materials:

1). Carbon Fibre Composites

Carbon fibre composites are one of the most promising materials for pressure vessels due to their high strength-to-weight ratio, corrosion resistance, and durability. Carbon fibre composites are made by weaving together carbon fibres and then coating them with a resin matrix. These composites are used in various industries, such as aerospace, automotive, and energy, for applications such as hydrogen storage and fuel cells.

2). Hybrid Materials

Hybrid materials are a combination of different materials that offer unique advantages for pressure vessel applications. For example, a hybrid pressure vessel could use a carbon fibre composite exterior for high strength and durability, with a metallic interior liner for improved gas compatibility. Hybrid materials also offer the potential for tailoring the material properties to meet specific application requirements.

3). Other Emerging Materials

Other emerging materials, such as graphene and nanotubes, are also being explored for pressure vessel applications. Graphene is a two-dimensional material with exceptional mechanical and electrical properties, and it has the potential to improve the strength and durability of pressure vessels. Nanotubes are cylindrical structures made of carbon atoms and have high strength and flexibility, making them promising for use in pressure vessels.

Advances In Pressure Vessel Design

Additive manufacturing, also known as 3D printing, is a promising technique for pressure vessel design and fabrication. With this technique, pressure vessels can be printed layer by layer using a variety of materials, including metals, plastics, and composites. Additive manufacturing offers many benefits, such as reduced lead times, increased design flexibility, and the ability to produce complex geometries that are difficult to fabricate using traditional manufacturing techniques.

Computational modeling is another promising approach for pressure vessel design. With this technique, pressure vessels can be designed and optimised using advanced computer simulations. These simulations can accurately predict the behavior of pressure vessels under different conditions, such as varying pressures and temperatures, and can help optimise the vessel design for improved performance and safety.

Optimisation techniques are used to improve the design of pressure vessels by minimising weight, maximising strength, and reducing manufacturing costs. These techniques use advanced algorithms and software tools to explore a range of design options and identify the optimal design for a given application. Optimisation techniques can help reduce material waste, improve efficiency, and enhance the performance and safety of pressure vessels.

Safety And Maintenance Of Future Pressure Vessels

Safety is of utmost importance in pressure vessel technology, as any failure or malfunction can have severe consequences. It is essential to ensure that pressure vessels are designed, fabricated, and tested to meet industry standards and safety requirements to prevent accidents and ensure the integrity of the vessels. Safety considerations should be taken into account during all phases of the pressure vessel life cycle, from design to disposal.

Regular Inspection And Maintenance Of Pressure Vessels

Regular inspection and maintenance are necessary to ensure the continued safe operation of pressure vessels. Inspection techniques, such as visual inspections, non-destructive testing, and pressure testing, are used to detect any defects or signs of deterioration. Maintenance tasks, such as cleaning, painting, and repair, are also essential for the upkeep of pressure vessels. The frequency of inspection and maintenance depends on the type of pressure vessel and its usage, but it is typically recommended to have them inspected and maintained at least once a year.

Preventing Pressure Vessel Failures

Pressure vessel failures can occur due to various reasons, including corrosion, fatigue, and overpressure. To prevent failures, pressure vessels should be designed and fabricated to meet industry standards and safety requirements. Proper use, inspection, and maintenance of pressure vessels are also essential for preventing failures. Monitoring the pressure and temperature inside the vessel, using pressure relief valves, and ensuring the proper use of the vessel can also help prevent failures.

Final Thoughts

Sherwood Design & Engineering has a long and successful history of providing high-quality pressure vessel solutions for a wide range of industries. Our expertise in pressure vessel design, fabrication, and testing, combined with our commitment to safety and customer satisfaction, has made us a trusted partner for many companies around the world. As pressure vessel technology continues to evolve and advance, it is clear that Sherwood Design & Engineering will continue to be at the forefront of this industry, providing innovative and efficient solutions to meet the needs of our clients.

Give us a call at (02) 9437 3566 or leave an enquiry if you would like to learn more about our pressure vessel engineering design and support services.

Pressure vessels are essential components of many industrial processes because they are used to store and transport gases and liquids under high pressure. The design of these vessels is crucial to ensuring their safe and dependable operation, and one crucial component of that design is the incorporation of external nozzle loads. External nozzle loads are the forces and moments that piping, equipment, and other externally attached parts exert on the pressure vessel. If these loads are not properly taken into account during the pressure vessel design, they can result in significant stress and deformation, which could lead to failure and pose safety risks.

We will discuss the various loads that can be applied to pressure vessels, the methods used to analyze and calculate these loads, and the design considerations that must be taken in order to guarantee their safe and dependable operation in various industrial applications. Whether you are a mechanical engineer, a plant operator, or simply interested in how industrial processes work, this blog will provide insightful information about the critical role that external nozzle loads play in pressure vessel design.

Types Of External Nozzle Loads

It is crucial to take into account the external nozzle loads that the pressure vessel will experience while in use when designing the pressure vessel. There are various types of these external loads, including:

1. Thermal loads: These are brought on by the piping that is connected to the nozzle’s thermal expansion or contraction. The piping expands or contracts as the temperature of the fluid inside the vessel changes, which can exert strong forces on the nozzle.
2. Weight loads: These are brought on by the weight of any attached machinery and the piping that is connected to the nozzle. The nozzle may bend or deform as a result of the equipment’s heavyweight.
3. Wind loads: These are brought on by the wind’s force on the nozzle-connected piping and machinery. Particularly if the vessel is situated in an area with high wind speeds, wind loads can be very high.
4. Seismic loads: These are brought on by the ground shifting during an earthquake. The nozzle may experience significant forces from seismic loads, particularly if the vessel is situated in an earthquake-prone area.
5. Pressure loads: These are brought on by the fluid pressure inside the vessel. The nozzle needs to be built to withstand the loads because the pressure can exert sizable forces on it.

Methods For Calculating External Nozzle Loads

Calculating external nozzle loads is a critical step in pressure vessel design, as failure to properly account for these loads can result in catastrophic failure. There are several methods for calculating external nozzle loads, each with its own advantages and limitations. Here are a few commonly used methods:

1). WRC 107 and WRC 297 Methods

These methods were developed by the Welding Research Council (WRC) and are widely used in pressure vessel design. WRC 107 is applicable for external loads that are applied perpendicular to the nozzle axis, while WRC 297 is applicable for loads that are applied at an angle. These methods are based on experimental data and provide conservative estimates of the maximum allowable loads.

2). Finite Element Analysis (FEA)

FEA is a numerical method used to analyse the behaviour of structures under loading conditions. It is a powerful tool for calculating external nozzle loads, as it allows for the modelling of complex geometries and loading conditions. FEA requires a detailed understanding of the structure being analysed and is best used by experienced engineers.

3). API 650 and API 653 Methods

Tanks with external nozzles are frequently designed using these techniques. While API 653 is used for tank repairs and modifications, API 650 is used for new tank construction. Based on the geometry, material characteristics, and operating circumstances of the tank, these methods offer guidelines for the maximum allowable loads.

4). ASME Section VIII, Division 2

The design of pressure vessels with external nozzles is governed by this code. It has provisions for calculating nozzle loads according to the geometry, orientation, and loading circumstances of the nozzle.

It’s crucial to remember that these approaches are not mutually exclusive, and engineers may combine approaches to get the most precise results. Additionally, some techniques might be better suited for a specific class of pressure vessel or set of loading circumstances than others. A qualified engineer should assess each situation separately and choose the best strategy for the circumstances.

Design Considerations For Incorporating External Nozzle Loads

A number of factors need to be carefully taken into account when designing a pressure vessel that can withstand external nozzle loads. Following are some design factors for including external nozzle loads:

1). Allowable Stresses

The designer must make sure that the stresses brought on by the external nozzle loads are within the tolerances for the pressure vessel’s material. The designer should determine the stresses and make sure they are within acceptable limits using suitable stress analysis methods, including finite element analysis (FEA).

2). Nozzle Stiffness

On the stresses brought on by external loads, the stiffness of the nozzle can have a significant effect. For the nozzle to have enough stiffness to handle the loads, the designer should take the nozzle’s geometry and thickness into account.

3). Nozzle Orientation

The stresses induced in the vessel may also depend on how the nozzle is positioned in relation to the applied loads. The orientation of the nozzle and its interaction with the external loads should be taken into account by the designer.

4). Support Conditions

The support conditions of the pressure vessel and the nozzle can also have an impact on the induced stresses. The designer should consider the support conditions and ensure they are appropriate for the loads and geometry of the nozzle.

5). Fatigue Life

The designer should also consider the fatigue life of the pressure vessel, taking into account the cyclic loading induced by external nozzle loads. Fatigue life analysis should be performed to ensure the vessel will have an acceptable service life.

Final Thoughts

To ensure the safety and integrity of the vessel, it is essential to incorporate external nozzle loads into pressure vessel design. Different kinds of external nozzle loads, such as pressure thrust, moments, and forces, must be taken into account. The vessel’s ability to withstand these loads can be increased through the use of suitable calculation techniques and design considerations, such as the choice of suitable materials and supports. 

Ultimately, the key to ensuring a secure and effective design is to collaborate with experienced engineers who are familiar with the pertinent codes and standards. Pressure vessels can be designed and built to meet the specific needs of your company while ensuring safety and regulatory compliance with careful planning and attention to detail.

Contact Sherwood Design & Engineering Today

If you are in need of pressure vessel design and engineering services, including the incorporation of external nozzle loads, Sherwood Design & Engineering can provide expert assistance. With over 40 years of experience in the industry, our qualified engineers can design pressure vessels to Australian Standards and provide detailed calculations and drawings. Contact us today to discuss your project needs and how we can help.

Give us a call at (02) 9437 3566 or leave an enquiry if you would like to learn more about our pressure vessel engineering design and support services.

 

 

 

 

In many industrial processes, from the production of chemicals and petrochemicals to the storage of gases and liquids, pressure vessels play a crucial role. Even though these vessels are built to withstand extreme pressure and heat, they all eventually wear out.

In this blog post, we’ll look more closely at the variables that affect a pressure vessel’s lifespan and the actions that may be taken to increase it. This post is for you whether you’re thinking about buying a new pressure vessel or simply want to learn more about how to maintain your current one.

Factors That Determine The Lifespan Of A Pressure Vessel

A pressure vessel’s lifespan depends on a number of variables. By being aware of these variables and taking action to solve them, it is feasible to increase a pressure vessel’s lifespan and guarantee that it continues to function safely and effectively for many years to come. These are a few of the most crucial elements.

1). Material Of Construction

The kind of material utilised to build a pressure vessel has a significant impact on how long it will last. Some substances, including carbon steel and stainless steel, are renowned for their longevity and corrosion resistance. Others, like aluminium and other alloys, might have shorter lives since they are prone to corrosion and deterioration over time.

2). Operating Conditions

The longevity of a pressure vessel is also influenced by the way it is used. For instance, a vessel operating at high temperatures or pressures will be exposed to more stress and degeneration than one running at lower temperatures or pressures. The kind of fluid or gas that is kept inside the vessel might also have an effect because certain substances are more corrosive than others.

3). Quality of Manufacturing and Maintenance

The quality of the manufacturing process and the level of maintenance a pressure vessel receives can also play a role in determining its lifespan. A vessel that is poorly manufactured or poorly maintained will have a shorter lifespan than one that is made to high standards and well-maintained.

4). Inspection and Testing

A pressure vessel can benefit from routine testing and inspection to detect any problems early on, allowing for quick repairs or replacements. The lifespan of the vessel may be extended as a result.

How To Prolong The Lifespan Of A Pressure Vessel

Proper care and maintenance are key to prolonging the lifespan of a pressure vessel. Here are a few steps you can take to ensure your vessel lasts as long as possible:

1). Proper Maintenance

A pressure vessel must get regular maintenance to remain functional. This includes routinely cleaning and inspecting the vessel, as well as doing any necessary repairs or replacing worn-out or damaged parts.

2). Proper Operating Conditions

You can ensure that your pressure vessel will not be subjected to undue stress or wear and tear by operating it within the advised range. This entails neither overloading nor overfilling the vessel, as well as employing the proper pressure and temperature restrictions.

4). Regular Testing and Inspection

Regular pressure vessel testing and inspection can aid in spotting possible difficulties early on, enabling repairs or replacement to be undertaken before they worsen. The lifespan of the vessel may be extended as a result.

5). Adequate Safety Measures

Proper safety measures such as safety valves, overpressure protection devices, and pressure relief valves are important to prolong the lifespan of a pressure vessel.

Final Thoughts

The building material, operating circumstances, manufacture and maintenance standards, as well as routine inspection and testing, all affect a pressure vessel’s lifespan. A pressure vessel’s lifespan can be increased and its ability to function safely and effectively for many years to come ensured by being aware of these variables and taking action to solve them.

Sherwood Design & Engineering offers a range of pressure vessel services including design, engineering, verification, and registration. 

If you are looking for trustworthy and reliable pressure vessel engineering design and support services, please call us today on (02) 9437 3566 or leave an enquiry.

 

 

A pressure vessel is an air-tight container mostly used in petrochemical and refinery plants to process fluids or hold or carry gases or liquids. They are commonly exposed to pressure loading along with external or internal operating pressure which is different from “ambient pressure”. 

Pressure vessels also store energy in high amounts. The larger the vessel and the higher the operating pressure is, the more energy will release if a rupture occurs. As a result, this increases the extent of disaster, damage, or danger that it poses. For this reason, there should not be any complacency involved when it comes to these risks. 

If you want to learn more about the serious hazards in pressure vessels, keep reading today’s blog article as we discuss this in more detail.

What Causes Pressure Vessel Failure?

If a pressure vessel fails, this can lead to several serious hazards. Because of this, it’s important to be aware of the causes of pressure vessels. The primary causes of pressure vessel failure include the following:

• Poor maintenance or operator errors
• Faulty design
• Operating the vessel above the maximum allowable working pressure
• Over temperature
• Improper installation
• Cracking
• Corrosion
• Material defects
• Welding problems
• Low-water condition
• Burner failure
• Over pressurisation
• Fabrication error
• Unsafe alteration or modifications
• Not sticking to a regular inspection schedule

Hazard Awareness In Pressure Vessels

The potential hazards linked with pressure vessel failure when not properly constructed, designed, operated, tested, repaired, or inspected include:

• Fragmentation damage
• Blast effects
• Poisoning
• Suffocation
• Chemical burns
• Fire explosion
• Loss of property and lives
• Thermal burns
• Loss of income/earning
• Permanent disabilities or injuries on the affected people

One of the most serious hazards is when pressure vessels have not been modified, welded, or installed properly, or if the pressure vessels are lacking an effective pressure relief system. Even liquids and gases classified as non-dangerous can become dangerous in any accidents that involve high-pressure equipment. 

Why Should You Register Your Pressure Vessel Design?

If your pressure vessel falls under hazard levels A, B, C, or D, the design must be registered or else you could be liable for fines. 

The process involved in pressure vessel design registration and verification includes comparing the vessel design to the design requirements of nominated international standards, according to the stated operating and design conditions. These processes are in place to make sure the design is fully compliant and to ensure the equipment includes enough structural integrity for all in-service conditions in the way of matching requirements set out by the relevant standards. 

Precautionary Measures To Avoid Pressure Vessel Hazards

Catastrophic disasters that are caused by accidents involving pressure vessels can be almost completely prevented by:

• Making sure the pressure vessel is designed, fabricated, and constructed so that it complies with applicable standards and codes with the assistance of a company like Sherwood Design & Engineering.
• Making sure the vessel operates at a pressure that is under the “maximum allowable working pressure” with the correct pressure setting for the relief devices, to deal with temperatures and design pressures. 
• Periodically inspecting and testing the pressure vessel and relief devices to detect erosion or corrosion that could lead to leaks, cracks, holes, or any other defect. 
• Removing the safety-relief valves during a safety inspection to ensure the settings are accurate. 
• Maintaining inspection report records and monitoring any potential issues to ensure the vessel is removed from service well before it has a chance to become hazardous. 
• Ensuring that repairs or alterations are only carried out by authorised and competent professionals and that the repairs match the acceptable industry-quality standards relating to pressure vessel repair. 
• Providing employees with safety training on anticipated conditions and job hazards that could risk their safety or the safety of others. 

Final Thoughts

Accidents involving pressure vessels cannot be avoided fully, but companies can work on reducing the risks significantly and the probability of these accidents occurring. Sherwood Design & Engineering offers a range of pressure vessel services including design, engineering, verification, and registration. At Sherwood Design & Engineering, we are here to help our clients with all their pressure vessel needs.

If you are looking for trustworthy and reliable pressure vessel engineering design and support services, please call us today on (02) 9437 3566 or leave an enquiry.

Pressure vessels are used in a wide range of industries for various purposes. There are different types of pressure vessels that are classified on the basis of several criteria. In today’s blog post, we will take a close look at the types of pressure vessels, the classification of pressure vessels, and the material selection for pressure vessels.

What are Pressure Vessels?

Pressure vessels are enclosures that are capable of holding gases, vapours, and liquids at a huge pressure difference compared to ambient pressure. These are used in a wide range of industries including the food processing industry, chemical industry, oil and gas industry, and petrochemical industry, among others. Some examples of pressure vessels include heat exchangers, reactors, and separators.

Classification of Pressure Vessels

Pressure vessels are typically categorized into the following classifications:

• Pressure classification
• Shape classification
• Role classification
• Dimension classification
• End construction

Keep reading below to learn more about the various types of pressure vessel classifications. 

1). Pressure Classification 

Pressure vessels can be classified on the basis of pressure levels. These pressure levels include ultra-high pressure, high pressure, medium pressure, and low pressure.

2). Shape Classification

When it comes to shape or geometry, you will find that there are spherical vessels and cylindrical vessels. Spherical vessels are typically used to store high-pressure fluids where their spherical shape ensures even distribution of internal and external stresses. On the other hand, cylindrical vessels have a cylindrical shell and a number of heads. A cylindrical shape is the most widely used as it is cheaper to produce; however, they are not as strong as spherical-shaped vessels.

3). Role Classification

Pressure vessels may also be classified on the basis of their role in the process such as a reaction container, heat exchange container, storage container, transportation container, or separation container. A reaction container is used for carrying out physical and chemical reactions whereas a heat exchanger is used for completing heat exchange. 

Meanwhile, a separation container is used for gas separation or gas purification or medium exchange.  A storage and transportation vessel is used for the storage and transportation of media or for balancing and buffering the pressure.

4). Dimension Classification

Pressure vessels are also classified on the basis of the thickness of the shell. If the wall is less than 1/10 of the shell diameter, the vessel is known as a thin shell. If the wall thickness is higher than 1/10 of the shell diameter, it is called a thick shell vessel. The thin shell vessels are used in pipes, tanks, and boilers whereas thick shells are used as gun barrels, tanks, and high-pressure cylinders.

5). End Classification

This classification is based on the end construction which can be open-ended or close-ended. A piston is an example of an open-end construction whereas a tank would be a close-ended vessel.

Material Selection for Pressure Vessels

Pressure vessels are constructed using a wide range of materials. The material is chosen based on several criteria such as corrosion resistance, strength requirements, ease of fabrication, ease of maintenance and budget.

Needless to say, the chosen material must be capable of withstanding certain levels of internal and external stresses The material should also be capable of withstanding the environment where it is going to be installed. It is not easy to fabricate pressure vessels using any material. Material needs to have proper weldability and machinability.

Some of the common materials used for the construction of pressure vessels include:

1). Stainless steel — It is a type of steel with chromium content ranging from 10.5 to 30% with trace amounts of nickel and lower carbon content. Stainless steel has excellent corrosion and chemical resistance properties. It has higher elasticity and ductility as compared to carbon steel.

3). Carbon steel — Carbon steel has a carbon content of up to 2.5% and it is known for high tensile strength which makes it useful for various applications. However, it is difficult to bend into certain shapes due to its high tensile strength and is more prone to corrosion as compared to stainless steel.

3). Aluminium — It is a material with a high strength-to-density ratio. It is also much cheaper and easier to fabricate as compared to stainless steel. On top of that, it has excellent corrosion resistance but it is not suited for high-pressure applications.

4). Titanium — It has excellent strength along with corrosion resistance. Its melting point is also higher than aluminium and steel which makes it suitable for high-temperature applications. Its high thermal conductivity makes it the perfect material for heat exchangers.

Final Thoughts

To conclude, pressure vessels are used in a wide range of industries. They can take form as a variety of shapes and are classified on various basis as explained above. When it comes to choosing a material for constructing a pressure vessel, it should be chosen on the basis of strength, corrosion resistance, and other end requirements.

Register Your Pressure Vessel Design

The pressure vessel design registration and verification make sure that your pressure vessel meets the required standards. The registration process is focused on equipment safety. Design registration is also mandatory for certain types of pressure vessels.

Sherwood Design and Engineering is a premier design and manufacturing agency of pressure vessels that meet the required standards. Our team can also make recommendations for engineers to ensure final inspection and sign-off before registration.

Give us a call at (02) 9437 3566 or leave an enquiry if you would like to learn more about our pressure vessel engineering design and support services.

Pressure vessels are containers designed to hold fluids at a pressure substantially lower or higher than the ambient pressure. They are used in a variety of potentially dangerous situations, from industrial boilers to petrol tankers. They facilitate secure storage of pressured liquids and gases, hence are a vital component of many industrial and processing facilities. 

However, if not properly designed, constructed and maintained, they can be exceedingly dangerous. In fact, throughout history, poorly designed pressure vessels have been known to cause catastrophic accidents. That led to the invention of the ASME (American Society of Mechanical Engineers) code, also known as the ASME Boiler & Pressure Vessel Code (BPVC). 

The code regulates the design, development and construction of pressure vessels, and its rules apply to Australia as well as 60 other nations. In this post, we’re going to be looking at 2 design methods used by engineers to design pressure vessels. 

What Is Pressure Vessel Design by Analysis (DBA)?

The ASME code Section viii has three divisions outlining the rules of pressure vessel design. Section viii division 1 focuses on the design-by-rule method while division 2 focuses on a design-by-analysis method. The design by analysis method offers guidelines for designing pressure vessels using numerical analysis (usually finite element analysis). 

This requires more detailed calculations than division 1 and seeks to protect pressure vessels against 5 types of failure—collapse from buckling, local failure, plastic collapse, cyclic service: fatigue and cyclic service: ratcheting. Seeing that it focuses on maximum distortion energy, it yields pressure vessels that can tolerate greater strains, though comes with an additional cost. 

What Is Pressure Vessel Design by Rule (DBR)?

This is a less comprehensive design method contained in ASME section viii, division 1. It is a conservative method used by engineers to size pressure vessels in accordance with their application requirements and bases its calculation on normal stress energy. 

It outlines guidelines for designing pressure vessels with the help of closed-form equations and other stringent regulations. The Design by Rule approach yields pressure vessels that can withstand common failure modes. 

A Brief History of Pressure Vessel Design

So where did the concept of pressure vessel design come from? The earliest known theory of pressure vessel design was developed by Renaissance painter, engineer and draftsman, Leonardo da Vinci. He developed a hypothesis in 1495 where he described how he lifted weights underwater using “containers containing compressed air.”

Though his publication was made, his assumption was flawed. After centuries of numerous failed design iterations, and hazardous mishaps to create secure pressure vessel designs, we have now established design methods that work. Today, the ASME code enforces the adoption of standard standards for the design and development of pressure vessels through the BPVC (Boiler and Pressure Vessel Code).

How to Size a Pressure Vessel

To size a pressure vessel, a design engineer should first gather data around parameters that affect pressure vessel performance. These include the vessel’s purpose, its location’s size, shape, and orientation, the type of vessel head to be used, the construction materials to be used, the interior fittings, and the operating circumstances, such as the temperature and pressure of the surrounding environment, as well as process materials and services (deposits and corrosion). 

Following preliminary data collection, standard procedures outlined in BPVC Section VIII, which is further divided into subsections, appendices and guides should be used. They help determine material requirements, fabrication requirements and general design requirements. This effectively sizes the pressure vessel.

How to Design a Pressure Vessel: By Analysis

To design a pressure vessel by design, the following steps are employed:

• Data collection for a complete specification of the service conditions.
• Establishment of a preliminary layout as per relevant design codes and information on material properties.
• Conducting an elastic stress analysis to analyse the possible modes of failure. Because the most common modes of failure are stress-dependent, determining the stresses and setting acceptable limits are critical steps in this design process.
• Computational technologies further permit engineers to develop cost-effective pressure vessels.

How to Design a Pressure Vessel: By Rule

Designing pressure vessels by rule involves the following steps:

• Assessment of pressure vessel function, size and other necessary parameters.
• Design preparation using standard vessel geometries using simple formulae and charts. This involves calculating the minimum required thickness of the vessel using design pressure, allowable stress, and a design formula compatible with the geometry of the part.
• Codifying geometries using standards and codes based on the rules proposed in the European Standard prEN13445-3 and ASME BPVC. 
• The Code design also outlines basic rules that specify the design method, and design load. The certification requirements, acceptable materials and allowable stress for fabrication inspection for the construction of vessels are also obtained from the code.

Final  Thoughts

Because of the ability to consider higher allowable stresses and obtain more real, economic, and reliable results, there has been a significant shift toward using the design-by-analysis method. This provides a more rigorous analysis, especially for vessels subjected to complex loadings such as cyclic, thermal, or localised loads.

Register Your Pressure Vessel Design

Sherwood Design & Engineering provides comprehensive pressure vessel design services. We can produce detailed pressure vessel drawings, ready for manufacture, using our 3D modelling and design drafting technologies. 

We also supply the calculation set as well as drawings as part of the package and can facilitate independent third-party verification for all our designs for registration with the relevant authority. Let our qualified engineers help you design pressure vessels in accordance with Australian Standard AS 1210 and the ASME code. 

Give us a call at (02) 9437 3566 or leave an enquiry if you would like to learn more about our pressure vessel engineering design and support services.

 

 

One of the most important pieces of stationary equipment at any process plant is pressure vessels. These pieces of pressure equipment are found in just about every petrochemical, refinery or chemical plant. Available in both vertical and horizontal variants, pressure vessels are used to house major chemical processes. Pressure vessels can carry or process fluids under various pressure and temperature ranges. 

Most pressure vessels are designed in accordance with AS 4343 – this is the Australian standard designed to regulate the construction and design of any boiler and pressure vessel. 

To ensure that they effectively and reliably serve their purpose, pressure vessels are designed with a variety of important parts. Read on below for a comprehensive guide on the different parts of pressure vessels. 

What Are Pressure Vessels?

A pressure vessel can be defined as a specially designed container for holding fluids under high pressure. In general, there are different types of pressure vessels, including cylindrical pressure vessels (vertical or horizontal) and spherical pressure vessels.  

Parts Of A Pressure Vessel 

Here’s a breakdown of the main parts of a pressure vessel: 

Shell

Normally conical, cylindrical or spherical in shape, a pressure vessel shell is made of different plates welded to another and so forth, to form a structure with a common rotational axis. 

Depending on the intended application of the pressure vessel, the shell can be made using a variety of metals, including carbon steel. This material ensures maximum strength at minimal wall thickness. The wall thickness affects the level of internal pressurisation that can be handled by the resulting vessel.   

Head 

Designed to be dished, spherical or semi-elliptical, the heads act as enclosures to the ends of a pressure vessel. Most pressure vessels use curved heads for a number of reasons. In addition to being stronger, curved heads are also less expensive, thinner and lighter than their flat counterparts. 

Nozzle

Designed to penetrate the shell or head of a pressure vessel, a nozzle is a cylindrical component. These components have a number of uses, including providing direct attachment to other equipment like heat exchangers, attaching instrument connections like pressure gauges, piping for guiding the flow of fluids into and out of the vessel and providing access to the vessel at a manway.  

Base Plate 

Part of the pressure vessel support, the base plate is considered to be among the non-pressurised parts of these vessels. The base plate is a flat metal ring that rests on a concrete foundation and is welded to the vessel’s support skirt, at the bottom. To secure the vessel to the concrete foundation, the base plate comes with holes around the perimeter of the circular ring that is designed to be placed over anchor bolts. 

Skirt 

Also considered to be the main part of a pressure vessel’s support, the skirt can be defined as cylindrical-shaped support for vertical pressure vessels. The upper end is welded to the bottom head of a vertical vessel, while the lower end is attached to the base plate – allowing the vessel to rest on the foundation.  

Final Thoughts 

Pressure vessels are designed to hold fluids, including compressed air, at high pressures and in some cases high temperatures. To efficiently serve their purpose, these structures are designed with a variety of essential components, in accordance with Australian Standards. Different metal pressure vessels have different properties and are therefore used in different applications. 

Register Your Pressure Vessel Design With Sherwood Engineering

Are you a mechanical engineer looking to register your pressure vessel? Sherwood Design & Engineering can help you ensure that your vessel design is compliant with the relevant safety standard, and meets the requirements for safety. 

Give us a call at (02) 9437 3566 or leave an enquiry if you would like to learn more about our pressure vessel engineering design and support services.

Because each type of metal has its own limitations and provides its own unique benefits the choice of material for a pressure vessel will largely depend on the specific needs of the intended application. Failing to select the right material is a leading cause of pressure vessel failure. This is why selecting the appropriate metal for a specific application is critical. 

Improper selection can lead to a number of serious issues from poor performance and lower efficiency to reduced safety and ultimately catastrophic failure. It is mandated by the National Board of Boilers and Pressure Vessel Inspectors that a test report be provided when any pressurised tank is ordered. 

However, this has not been totally effective enough at preventing errors from occurring in the certification procedure and as a result, incorrect selection of pressure vessel materials remains commonplace. 

There are a number of different types of materials used in pressure vessel manufacturing, including carbon steel, stainless steel, Hastelloy, nickel alloy, aluminium, and titanium. Given the fact that failure of pressurised vessels can create a significant hazard that often leads to more downtime, higher production costs, and, most importantly, reduced safety – engaging a reputable manufacturer to help select the right material for a specific pressure vessel is crucial. 

What are Pressure Vessels? 

Pressure vessels are solid, leak-proof containers, usually cylindrical or spherical in shape, designed to hold fluids such as gases or liquids at pressures that are significantly different from the ambient pressure. The most common materials used for pressure vessels are carbon or stainless-steel plates rolled into shape and welded together to form a tank. 

Pressure vessels are essential for providing temporary storage, for example, for compressed air, before it is utilised. In addition, it helps a compressor system to run more efficiently. In a compressed air system a pressure vessel performs 3 primary functions: 

• Temporarily stores compressed air until there is a demand for it
• Provides steady air signs for air compressor controls 
• In wet pressure vessels, they play a secondary role in heat exchangers by enhancing the efficiency of the air dryer. 

Different Types of Pressure Vessels 

In general, there are three main types of pressure vessels – horizontal, vertical, and spherical. A few examples of the most widely used pressure vessels include: 

• Columns 
• Towers 
• Boilers 
• Separators 
• Bullet tanks 
• Heat exchangers 
• Knock-out drums
• Reactors 

All of these pressure vessels have varying temperatures and operating pressures and are extensively used in chemical/petrochemical processing, petroleum refining, oil and gas industries, and power plants. 

Top Material Ideal for the Manufacturing of Pressure Vessels 

The top four materials that are ideal for the manufacture of pressure vessels are: 

Stainless Steel 

The robust design and construction of stainless steel make it an ideal material for pressure vessels. Stainless steel grades have the best corrosion-resistant properties and are highly resistant to a wide range of chemicals. It is economical and ideal for use in high temperatures or humid conditions. 

Titanium 

Titanium’s many properties make it suitable for use in a pressure vessel. It has a great capability to retain its own structural integrity, is highly resistant to corrosion, and is ideal for use with harsh liquids like acids. It is non-toxic, low maintenance, and economical. 

Aluminium 

Aluminium’s tensile strength is its most beneficial attribute. It is more cost-effective compared to other materials in the range and has a slightly higher coefficient expansion compared to other alternatives. 

Nickel Alloy 

Nickel Alloy is the perfect material for the protection of both the constituents and the vessel from thermal expansion. With perfect resistance to corrosion, its oxidation and carburisation levels are perfect for pressure vessels. It can be relied on in hostile surroundings and is longer lasting than most other materials. 

Choosing the Right Material for Your Pressure Vessel 

The right material for your pressure vessel will largely depend on the type of vessel you will be using and the type of constituents it will be required to contain. The above four examples are an indication of each material’s qualities and features and could serve as a guide, however, it is highly recommended to obtain the professional advice of a trusted manufacturer of pressure vessels to avoid making any mistakes. 

The design of a pressure vessel must be undertaken with great care as these tanks operate under tremendous pressure and a ruptured vessel can cause extensive and sometimes irreversible damage to property and harm to mankind. The ASME Sec VIII code is there to govern the design of pressure vessels. Pressure vessels can be custom designed and manufactured according to your specific requirements. 

Registering a Pressure Vessel Design 

The process of design verification and registration of pressure vessels is to ensure that the design meets the minimum requirements of the nominated international standard for the stated design and operating conditions. The process is concerned more with the safety of the equipment than its functionality. If your vessel has a hazard level of A, B, C, or D, it is mandatory to register the design. Failing to do this means that you can be liable for a fine. 

At Sherwood Design and Engineering our highly qualified engineers design and manufacture pressure vessels to the Australian Standard AS 1210 code. We can recommend a Pressure Vessel Engineer to inspect the final design and sign off for Item Registration before the vessel is put into service. 

Give us a call at (02) 9437 3566 or leave an enquiry if you would like to learn more about our pressure vessel engineering design and support services. 

 

 

 

Do you want to design pressure equipment? Are you familiar with the design requirements for a typical ASME boiler and pressure? A poorly constructed pressure vessel is a potential source of danger despite being an integral part of ensuring that your liquids and fluids are safe.

Over the years, there have been numerous cases of flawed pressure vessels causing serious accidents. For this reason, this article will outline three factors and design requirements to consider during pressure vessel engineering. But first, what exactly is a pressure vessel?

What Is A Pressure Vessel?

A pressure vessel is a sealed container that can withstand pressure significantly higher or lower than the external pressure while holding liquids, gases, or vapours. It is useful in industries, including petrochemical, oil and gas, chemical, and food processing. It can also be used in a reactor, flash drum, separator, and heat exchanger

Each pressure vessel must be used within the established temperature and pressure ranges. Pressure vessels require extensive testing, are challenging to construct, and take a long time to complete. This ensures they won’t harm the environment if their contents accidentally leak out. 

Pressure vessels must reach the ideal pressure for a given application to function correctly, e.g., maintaining air in a scuba tank. They can send pressure directly or indirectly by using valves and release gauges. Pressures can range from 15 to 150,000 psi, and temperatures frequently exceed 400 °C (750 °F). The capacity of a pressure tank ranges from 75 litres (20 gallons) to thousands of litres.

Factors To Consider When Designing Pressure Vessels

Choosing to design a pressure vessel is not simple. The process is tiresome, expensive, and quite challenging. You cannot, however, forego the importance of having a pressure vessel at hand as it has various uses. Below are the top three factors to consider if you are seeking to design a pressure vessel.

1). Design: How you construct the pressure vessel is the most crucial consideration. A pressure vessel’s design should have enough pressure and weight to hold the contents efficiently. When designing a pressure vessel, some things to consider are static and dynamic pressures, corrosion, reaction forces, ambient and operating temperatures, and thermal and residual stress. The pressure vessel’s shape and degree of complexity are additional considerations.

2). Material: Steel is one of the most popular materials for pressure vessels because it has many advantages. Carbon and low alloy steels, duplex steels 2205 and 2507, 300 series, and high-temperature stainless steel are some of the most frequently used materials in fabrication. Aluminium and nickel alloys like Inconel, Monel, and Hastelloy are considered suitable for the task. Consider seeking advice from a knowledgeable stainless steel pressure vessel manufacturer for guidance through the various materials.

3). Construction: Each component to assemble a pressure vessel has a specific function. Ensure that the various components are per international standards before welding them together to create the ideal pressure vessels for your task. Good welding is crucial when it comes to pressure vessels, and doing it incorrectly may fail your potential pressure vessel. Consider taking the necessary safety measures to ensure the pressure vessel is sturdy and secure.

How To Design A Pressure Vessel

You must be careful when designing a pressure vessel as they operate under high pressure. A leaking or burst pressure vessel can cause irreparable damage to people and property. The foundation of constructing a pressure vessel is the ASME Section VIII code.

The code regards the following components as crucial in designing a pressure vessel:

• Internal and external design pressure
• Test pressure
• Design temperature
• Standard construction materials
• Support
• Loading

The pressure vessel design formula, according to the international design codes, is:

α = PD/2t

Where; α = tensile stress, P = internal pressure, D = shell diameter, and t = shell thickness.

According to the ASME Section VIII division, here is the formula for calculating the shell thickness:

t = PR/(SE – 0.6P)

Where; t = shell thickness, P = internal pressure, R = cylinder radius, S = tensile stress, and E = joint efficiency.

Final Thoughts

It’s crucial to consider everything that could have an impact on a pressure vessel when designing one. Additionally, you must carefully review the specifications to ensure that you include all the crucial details that may significantly impact the pressure tank’s longevity and dependability.

Register Your Pressure Vessel Design

Once you have published and registered your pressure vessel design, the pressure vessels constructed using your design will require to be registered with the relevant authority in Australia. In this regard, a pressure vessel inspector will examine your design sample before approving its registration.

Consult Sherwood Engineering for assistance with the final step of putting your pressure vessel into service. Our skilled verifiers have experience working with all of Australia’s registration bodies and can advise you on the registration process. Talk to us for assistance with your pressure vessel design verification and registration.

Give us a call at (02) 9437 3566 or leave an enquiry if you would like to learn more about our pressure vessel engineering design and support services.

Pressure vessels hold both toxic and non-toxic fluids. The slightest malfunctioning of a pressure vessel can cause significant harm to industrial workers. Are you worried about the safety of your workers when handling pressure vessels? Worry no more. 

At Sherwood Engineering, we make sure your pressure vessels are inspected thoroughly and in the right way. We understand that it is easy to forget about inspection dates. We keep clear records to ensure you do not miss out on an inspection. Please contact us today to access our quality services. 

What Is A Pressure Vessel? 

A pressure vessel is a container that holds vapours, gases, and hot liquids at a pressure higher or lower than the normal pressure. Each vessel has its pressure vessel safety limit. 

Types Of Pressure Vessels 

Pressure vessels are mainly classified according to their purpose. Here are the main pressure vessels you need to know. 

1). Storage Vessel

This type of pressure vessel is used to hold industrial-purpose gases and liquids. It can be used to store finished products or hold fluids used in manufacturing. Storage vessels are mainly made of carbon steel. 

2). Boilers

These types of pressure vessels are heat transfer equipment. Their primary purpose is to heat liquids. In most instances, they are used to change liquids into vapour form. They use fuel, nuclear power, or electric power as heat sources. The vapour formed is used to generate power for heat application. Boilers endure high pressure and thermal stress. 

3). Heat Exchangers

These pressure vessels are used to transfer heat between fluids. They experience a lot of stress due to temperature differences between the hot and cold liquids and hence need regular service inspection. 

4). Process Vessels 

These are containers where industrial processes occur. Internal pressures in the vessels are determined by the industrial process the vessels are used for and the transformation of the substance involved. Types of process vessels include: 

• Distillation Columns – These are used to separate mixed liquids based on their differences in volatility. 
• Chemical Reactors – These are used to contain catalysts and reactants during chemical reactions.
• Industrial Mixers – These are pressure vessels used to emulsify and homogenise substances. 

Top 5 Things You Must Know About Pressure Vessel Inspection 

Pressure vessel inspection is crucial in avoiding pressure vessel failure. Here is what you must know about pressure vessel inspection. 

1). Ensure that only certified professionals inspect accurate identification of weak areas in a pressure vessel.

2). Inspectors must adhere to established industry standards during an inspection.

3). An inspector could be required to conduct internal and external inspections as follows:

• Internal inspection is done when the vessels are empty to identify corrosion, wear, and tear levels. 
• External inspections can be done when the vessel is in operation and is carried out on the outside to examine the functioning of external components. 

4). Frequency of inspection depends on the hazard levels of a pressure vessel. You need to use the services of a competent person who will inspect your vessels and guide you on how frequently the inspection should be carried out. 

5). Pressure tests should follow inspection:

• Leak Tests – These are used to confirm the maximum leaks that can be allowed in vacuum and pressure vessels.
• Hydrostatic Tests – These are carried out to test the leaks and strengths of pressure vessels.
• Mechanical Integrity Tests – These are used to check buckling or instability on pressure vessels.
• Pneumatic Tests – These are carried out where traces of a testing medium are not allowed or recommended. They should only be carried out when necessary. 

What Is The Frequency Of Pressure Vessel Inspection?

For safe working, you should regularly inspect pressure equipment as per the manufacturer’s recommendations. Inspection relies on several factors, including hazard levels and the type of pressure level. 

Steam boilers should go through inspection and tests every year. Air receivers and steam receivers must go through inspection and running tests after every two years. 

Autoclaves need to go through two types of inspection. You should carry out an inspection and run tests after every two years. The external shell inspection and complete insulation removal should be done after six years. 

After every ten years, all types of pressure vessels need to have gone through at least one thickness gauging and hydrostatic test. 

Final Thoughts

The testing and inspection of pressure vessels should never be ignored. Pressure level inspection requirements are given to enhance industrial safety. Pressure vessels come in different types and designs and are used for different purposes. Similarly, they require different kinds of inspection that you should know. 

Register Your Pressure Vessel Design 

At Sherwood Engineering, we offer you professional inspection for all types and designs of pressure vessels. Our experts have years of experience and are all certified. 

 

Pressure vessels are used to store fluids under various pressures. Most pressure vessels in Australia are built to Australian Standards (AS). However, this doesn’t always guarantee long-term performance. This is because pressure vessels are used to store a variety of toxic and non-toxic substances that may have a short or long-term impact.

It’s critical to understand the mandatory requirements and applicable Australian Standards (AS) to ensure that your equipment is safe to use and avoid fines associated with non-compliance with current safety regulations and legislation in Australia. The vessels must be inspected and repaired regularly to prevent any unforeseen accidents.

What Is Pressure Vessel Inspection?

Pressure vessel inspections refer to the internal, external, (or both) inspection of the vessel’s condition. The frequency of inspections is usually specified in most pressure vessel standards. Pressure vessels should be inspected at least once every five years as a general rule. Before the vessel is put to work, it must be inspected after installation.

When inspecting pressure vessels, inspectors may:

• Gather visual information on the vessel’s condition, such as the state of the joints, welds, insulation, or structural connections
• Collect thickness data to see if the vessel has any issues caused by continued use
• Perform a stress analysis to see if the vessel is still safe to use, and
• Perform a hydrostatic pressure test on the vessel’s pressure release valves to ensure they are working correctly.

Benefits Of Pressure Vessel Inspections

1). Prevent accidents

Naturally, a pressure vessel operates under extreme pressure or vacuum. As a result, it is prone to accidents and can be dangerous if it fails. As a result, a pressure vessel inspection is required to assess the condition and verify compliance with technical standards.

2). Avoid Fines

Inspections of pressure vessels can also go a long way in helping you avoid fines for failing to adhere to current safety laws and legislation in Australia.

Pressure Vessel Inspection Requirements

Expensive fines may be imposed if you fail to inspect pressure equipment to comply with applicable regulations. It is the responsibility of the pressure vessel owner to ensure that any pressure equipment in operation is “Safe to Operate” certified and registered with the appropriate regulatory authorities in your state.

As per AS3788-Pressure Equipment-In-Service Inspection, a “competent person” must regularly examine and appraise boilers and pressure vessels classified as Hazard Level A, B, or C. 

Pressure equipment inspections are precisely defined in AS3788 and take place:

• During commissioning and/or recommissioning.
• During service – A periodic in-service examination is performed as dictated under AS3788 Table 4.1.
• Following repairs (pressure vessels must be hydrostatically tested after weld repairs).
• Pressure relief and safety valves are inspected and overhauled/bench-tested on a regular basis to ensure they are in safe operating condition.

How Regular Should You Inspect Pressure Vessels According To To As3788?

External and internal periodic inspection frequencies for some of the more prevalent types of pressure equipment are listed in Table 4.1 of AS3788:

• Air Receivers – 4 years for internal inspections and 2 years for external inspections 
• Above ground LPG gas vessels – 2 years for external inspections and 10 years for internal inspections
• Refrigeration Vessels – 2 years and 12 years for external and internal inspection, respectively.
• Accumulators – 2 years for external inspections and 12 years for internal inspections

Annual testing and inspection of pressure relief and safety equipment are crucial and are needed for you to keep your inspection certifications valid.

Inspection of pressure equipment is required by most states’ existing safety legislation, with harsh penalties for non-compliance.

Pressure Equipment Repairs

While these may seem obvious, verify you’ve addressed these needs while altering, fixing, or modifying pressure equipment, particularly shell repairs. You should do this:

• To assure correctness, the vessel has been examined and tested to the standard.
• To confirm that you have a strict repair and testing protocol in place, including the weld operation, post-weld heat treatment, NDT (Non-Destructive Testing) and inspection of the repairs.
• To make sure that qualified welding technicians perform all weld repairs.
• To check if the vessel is hydrostatically tested in accordance with industry standards.

Record Keeping

All tests and certificates, including repair processes and repairer qualifications, must be stored and maintained in an equipment file under most current state safety legislation.

As you can see, there’s a lot to consider and manage when it comes to pressure equipment registration, maintenance, inspections, repairs, and record-keeping!

AME can assist in reducing “pressure.” We provide independent technical expertise to ensure that your assets, equipment, plants, and systems are planned, built, and operated in line with industry standards, classifications, and regulatory requirements.

Pressure Safety Valve & Pressure Relief Valve Inspection Requirements

PSVs and PRVs require an annual third-party examination by a certified person to ensure they are undamaged and functional. Instead of testing, the valves can also be replaced once a year. That is more cost-effective for some businesses.

Final Thoughts

Pressure vessel checks are critical to avoid unforeseen mishaps and fines for failing to follow current Australian safety laws and regulations. This page has outlined all of the AS pressure vessel inspection requirements that you must follow to avoid fines.

Why Register Pressure Vessel Design?

To be a Pressure Vessel owner in Australia, you need to be registered by an authorised examiner. At Sherwood Engineering, we are authorised examiners ready to serve you.