8 General Welding Rules of ASME B31.3 and API 570 Available to Purchase

This chapter is to introduce you to the main general welding rules contained in API 570 and ASME B31.3. API 570 is for in-service inspection of process piping and therefore most welding carried out will be repair welds, rather than welds carried out on new systems. Much of API 570 is also concerned with the repair of corroded areas and on-stream systems (hot tapping) where process fluid is still being carried through the piping.

API 570 (section 8.2) makes it a mandatory requirement to comply with the welding rules contained in ASME B31.3 because it says that all repair and alteration weldingshallbe done in accordance with the principles of ASME B31.3. In practice, this will only be for areas that do not directly conflict with API 570 requirements.