Pressure vessels are containers that are built to hold gases, vapours, or liquids at high pressures, typically above 15 psig. Pressure vessels are commonly used in the chemical processing, pharmaceutical, brewing and petroleum refining industries as heat exchangers, boilers and storage tanks. Each vessel has its unique specifications and operating limits that are built-in by custom design and engineering often referred to as design temperature and design pressure. Exceeding these operating limits could damage the vessel or lead to catastrophic failure and loss of containment.
Industry Standards And Practices
Because they work under immense pressure, a faulty, leaking or ruptured pressure vessel can be extremely dangerous, causing potentially lethal gas/chemical leaks and even massive explosions. It is because of this that pressure vessel engineering must be done with utmost care and perfection. There are specific standards and industry best practices that guide the designing, construction, maintenance, and inspection of pressure vessels. Some of the key standards that all pressure vessels must adhere to include:
- API 510- The API 510 is a standard that governs In-Service alteration, repair, rating and inspection of pressure vessels.
- ASME VIII – This is a pressure vessel and boiler code that offers detailed requirements for the design, construction, testing, inspection and approval of various types of pressure vessels.
Pressure Vessel Engineering
There are 2 main approaches in pressure vessel engineering; engineering by code and engineering by analysis.
A pressure vessel can be engineered based on the formula and rules specified in the standards. Engineering by code allows you to build a vessel that is safe to work under the required design temperature and design pressure. More recent in pressure vessel construction is engineering by analysis. Engineering by analysis is used where the specifications or structure of a vessel are not covered by the available standards and design codes.
Pressure Vessel Engineers
Pressure vessel engineers are the professionals tasked with the designing, fabrication, testing, repair, maintenance and inspection of pressure vessels. They are the only people who are qualified and approved to undertake this highly technical work due to its sensitive nature. Pressure vessel engineers have experience in building pressure vessels that follow the relevant codes and standards. They also have the necessary skill set to offer sound advice on pressure vessel engineering based on analysis.
Many people in the pressure vessel industry consider the design standards and codes to be advisory, meaning various accommodations can be made in cases where the codes and standards simply do not apply. When an engineer wants to push the limits imposed by the design codes, the engineering by analysis approach is considered the best because it offers more accurate stress-testing results.
The different stress parameters, such as bending stress intensity, and membrane stress intensity or bending stress, can be assessed more precisely and accurately when an engineering by analysis approach is used in pressure vessel construction.
Engineering by Analysis Is Taking Over
Engineering by analysis is gradually overtaking the more conventional approach of pressure vessel construction which tends to lean more towards following rules rather than providing efficiency, safety and durability. More demanding designs in terms of safety and reliability together with the cost of production are the main factors that have contributed to this gradual advancement in pressure vessel engineering techniques.
Many customers and industry stakeholders are now calling for a review of the existing pressure vessel design codes and standards in order to provide a wide framework for pressure vessel engineers and designs. Although strict adherence to applicable codes and standards cannot be ignored, engineering by analysis should not be completely ruled out because of all the amazing benefits this approach has to offer.
At Sherwood Design & Engineering Pty Ltd, we have been providing engineering design and support services to industries such as steelmaking, minerals processing, water treatment, food/pharmaceuticals, materials handling, and many others for more than 40 years.
We specialise in pressure vessel design and pressure vessel design verification, as well as plant engineering where design, plant layout and preparation of arrangement, fabrication and manufacturing drawings are required.
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.