Allowable Undercut

[lenlawson]

What is the maximum allowable undercut for a pipe fillet weld under B31.3? Under B31.1?

 

[Seldom]

Sorry, but I can only help you with the B31.3.

As per the requirements of ASME B31.3 Addenda-2001, Table341.3.2-

Category D & Normal Fluid Service where fillet welds include socket and seal welds, and attachment welds for slip-on flanges, branch reinforcement, and supports:
Depth of undercut- ¡Â 1 mm (1/32in.) and ¡Â ¨ù of the wall thickness

Severe Cyclic Service:
Depth of undercut- Zero (no evident imperfections)

 

[MJCronin]

lenny.....

For B31.1 Power piping, review Chapter VI, "Inspection, Examination and Testing"....... See Section 136.4.2 "Visual Examination of Welds"

In this Section, undercut that is deeper than 1/32" is cause to reject.

Addtionally, vertified inspection people must perform the examination.

Good Luck !!!???

MJC