Is backweld allowed to correct root bead welding defects or misalignment on the inside (process side) of pipe?

Asked by jakangaru 7 years ago | 1 Answers

1 Answer

franchaze 7 years ago

Backwelding should not be permitted unless it meets at least one of the following conditions:

  • With proper PWHT at a sufficiently high temperature and adequate holding time to reduce residual stresses and lower hardnesses to less than 248 HV10 (Diamond Pyramid).
  • The adequacy of the PWHT procedure should be demonstrated during welding procedure qualification testing
  • By performing the backweld repair before the second pass is applied