Pressure Vessels: A Guide to Understanding How They Work

Pressure Vessels: A Guide to Understanding How They Work

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.