What is the difference between ASME B31.1 and B31.3?

The biggest difference between ASME B31.1 and B31.3 is their requirements. In fact, although these codes are often used in conjunction, they vary significantly in their CRN registration requirements.

Some of the most common differences between ASME B31.1 and B31.3 include scope, allowable strengths, unlisted material specification, non-service hydro pressure testing, pneumatic pressure testing, service testing, alternatives to pressure testing, radiography and ultrasonic testing, minimum design metal temperature (MDMT) and impact testing requirements.

Although these codes differ extensively, equipment that meets ASME B31.1 and B31.3 requirements is possible to design and develop. Products that meet both standards can also receive CRN registration. The benefit of designing and registering equipment that meets all requirements is that it can be sold to a larger number of buyers.