For circumferential butt weld reinforcement, what is the maximum thickness allowed?

For circumferential butt weld reinforcement, what is the maximum thickness allowed?

• A. 1/8 in
• B. 1/4 in
• C. 3/16 in
• D. 1/32 in

Answer: (A)

Weld reinforcement is the extra metal that sits above the base pipe surface at the weld. For circumferential butt welds in standpipe piping, NFPA 14 limits that convexity to keep the inside bore as close to the nominal pipe diameter as possible. Too much reinforcement reduces the internal cross-sectional area, which can affect flow and system hydraulics, and it can complicate inspection and hydrostatic testing. Because of these concerns, the maximum allowed thickness is 1/8 inch. If a weld crest is thicker than that, it should be ground back to the pipe surface to meet the requirement. The other options would either exceed what the code permits or are too small to meet code expectations.

Weld reinforcement is the extra metal that sits above the base pipe surface at the weld. For circumferential butt welds in standpipe piping, NFPA 14 limits that convexity to keep the inside bore as close to the nominal pipe diameter as possible. Too much reinforcement reduces the internal cross-sectional area, which can affect flow and system hydraulics, and it can complicate inspection and hydrostatic testing. Because of these concerns, the maximum allowed thickness is 1/8 inch. If a weld crest is thicker than that, it should be ground back to the pipe surface to meet the requirement. The other options would either exceed what the code permits or are too small to meet code expectations.