Welding reinforcement pad on pressurized pipe 1

[Carlos Avelar]

Has anyone experienced welding a reinforcement pad or pipe support on piping that has pressure behind it? Is this allowed?

Variables are:
-New construction.
-Stainless steel pipe, Grd. 304L
-Nitrogen blanket @ 300 psi
-Repad material 3/8" rolled plate, Grd. 304L

Your input is greatly appreciated.

 

[0707]

Hot tapping uses welding reinforcement pads under controled pressure.

luis

 

[weldstan]

It is not disallowed under B31.3. But what is the diameter and thickness of the pipe? And it is assumed that nitrogen is not flowing? You need to prepare for the safety of the addition and determine the welding process and welding parameters to accomplish the weld safely.

 

[weldstan]

While I have written numerous hot tapping or repair welding of pressurized pipe, T sense that you have no experience in this matter. Advise hiring a consultant to assist you in your repair/addition or a contractor fully experienced in hot tap type repairs.

 

[Dhurjati Sen]

Consult API RP 2201, specially Sec 6.2 Burn through prevention. Although you are not doing hot tapping, but that's what you need to be careful about.

DHURJATI SEN

 

[Ali Meshaikhis]

ASME PCC-2
Repair of Pressure Equipment and Piping

This Standard provides methods for repair of equip- ment, piping, pipelines, and associated ancillary equip- ment within the scope of ASME Pressure Technology Codes and Standards1 after they have been placed in service. These repair methods include relevant design, fabrication, examination, and testing practices and may be temporary or permanent, depending on the circumstances.

The Standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this Standard to establish appropriate safety and health practices, and determine the applicability of regulatory limitations prior to use.