Welding to the exterior of an in-service pipe (304L)

Date 04-13-2012 21:00

Does B31.3 have anything to say about welding to the exterior of a pipe (304L SCH10) while that pipe is in-service and under pressure? The application is welding a saddle on the exterior of the pipe for others to come in at a later date to do a hot tap. The service is county water.

By G.S.Crisi (****)

Date 04-13-2012 21:21

Sorry I can't help you, I don't know if B31.3 says somehing. If not (and someone in this Forum will say), and since the service is county water, try the American Water Works Association (AWWA): www.awwa.org
Giovanni S. Crisi
Sao Paulo - Brazil

By TAC

Date 04-16-2012 16:07 Edited 04-17-2012 17:24

AWWA Section 3: Fabrication of Pipe - 3.3.3.1 states welding operators be qualified under Sec. IX, AWS B2.1, or any code mutually agreed on between purchaser and manufacturer.

Hope this helps.

Good luck...

By MBSims

Date 04-13-2012 22:11

I don't think B31.3 addresses welding of items after placed in service. However, hot taps on carbon and stainless steel are common and this should not be a problem.

By welderbrent (*****)

Date 04-14-2012 02:31 Edited 04-14-2012 02:47

The County, maybe through the water service provider, should call out the code that they want followed for the installment of saddles for hot taps.

edit: Did a forum search on 'hot taps', possible that API 1104 Appendix B will be what you are looking for. But I still think you will want to talk with the 'owner' of the system.

Have a Great Day, Brent

By FloridaSnook (**)

Date 04-14-2012 14:26

Looks like API 2201 has the information and direction I need.