The American Society for Mechanical Engineers, or ASME, is a not-for-profit organization meant for encouraging global collaboration, knowledge sharing, and skill development across the worldwide engineering community. ASME has continued to pioneer the development of standards in order to maintain a commitment to public safety as well as technological advancement.
The certifications that ASME requires specifically for pressure vessels are what we’ll be going over today. The ASME code for these types of equipment defines a number of mandatory requirements, non-mandatory guidance, as well as very specific things that are not allowed when designing and building pressure vessels, selecting the materials, inspecting and testing the vessels, as well as how to properly certify them.
This is just an overview of the basics of ASME certification for specific pressure vessels. For more detailed information, visit ASME’s website.
ASME Section VIII – a quick overview
The ASME code begins with defining what the code is meant to regulate–pressure vessels that operate at pressures either internal or external that exceed 15psi, and can be fired or unfired. This is a little different from other parts of their code, which define the regulations for other, more specific types of boilers or equipment.
The code for Section VIII pressure vessels is split into three specific divisions. The first covers what was mentioned above–guidelines for designing and building the vessels, how to inspect and test them, and other requirements and prohibitions that are important. However, the first division is specifically for pressure vessels undergoing a pressure of up to 3000 psi. Division One criteria also defines how equipment is marked once certified, either with U, UV, or UM designators.
- U indicates that the pressure vessel adheres to ASME’s latest guidelines
- UV indicates that a company is qualified and approved to assemble pressure relief valves for section VIII pressure vessels
- UM indicates that the company’s quality control system follows ASME’s latest guidelines
The standards under Division Two are a little more rigorous and can be applied to ‘human occupancy’ pressure vessels, such as diving equipment. This division covers similar mandatory requirements to Division One; however it also includes alternative rules that are specific to equipment with an internal or external pressure between 3000 psi and 10,000 psi–higher than average, but not quite meeting the definition of a ‘high’ pressure vessel. This division also uses the UV indicator for certification as well as another:
- U2 marks that the pressure follows the Division 1 standards as well as the alternative rules in Division 2
Division Three picks up here, at the rules and regulations for constructing a pressure vessel that has an internal or external pressure that goes beyond 10,000 psi, with no maximum limit defined. It also has different certification marks, UV3 and U3, similar to the Division Two indicators, but applying the Division Three alternative regulations for high pressure vessels.
Understanding the importance ASME Certification
ASME Certification is an indicator that a product was built to maintain safety regulations, and to be reliable at the same time. These guidelines give highly detailed requirements not just on the design and fabrication of a fire/unfired pressure vessel, but also on its assembly, inspection, testing, and certification. Having an ASME certification indicates that the manufacturer is producing equipment that not only complies with local regulations, but also with a globally recognized standard of quality and safety.
Does your process equipment require ASME Section VIII Certification?
At West Engineering, we manufacture all pressure vessels to ASME Code Section VIII and European TUV Code standards, ensuring product quality and customer safety. For quality, certified pressure vessels, check out West Engineering Co. today. We’ve been building custom machinery since 1919–over a century of experience in manufacturing high-quality equipment for our customers.