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Up Topic Welding Industry / Technical Discussions / vent hole in reinforcing pad
- - By ritz (*) Date 07-08-2008 11:04
Good day to all!

Im just new beginner and I just want to ask anybody and it my great pleasure for any response.

Why reinforcing pad for P.V. or Piping required a vent hole is there any impact if vent hole was not provided on pad.

Any comments is highly appreciated.

Ritz
Parent - - By 803056 (*****) Date 07-08-2008 11:36
The vent hole serves a couple of purposes.

1) it relieves any gas pressure that may develop when welding the pad to the nozzle or branch.
2) it is threaded so that it can be pressure tested to check for leaks.
3) it serves as a "telltale" if the weld underlying it develops a leak.
4) it prevents any build-up of pressure should the underlying weld develops a leak.

Hope that helps you.

Best regards - Al 
Parent - - By ritz (*) Date 07-08-2008 12:52
Hi AL,

Thanks you very much for your good technical reply, In follow up to my question, if the vent hole was not provided, is there any bad impact on P.V. during operations?

Thanks.

Ritz
Parent - By CWI555 (*****) Date 07-08-2008 12:57
The same logic applies to a presure vessel as does to a pipe.
Parent - By 803056 (*****) Date 07-08-2008 13:46
To my knowledge it is a violation of all ASME pressure vessel and piping codes. The reinforcing pads are not designed to be pressure retaining components. Should the vent be blocked or missing, a leak in the primary weld attaching the nozzle or branch could over pressurize the reinforcement and cause it to fail in an undesirable or unexpected manner, i.e., as in BOOM, shisssss, Kapow!

Best regards - Al
Parent - By jon20013 (*****) Date 07-09-2008 01:53
Ritz; at my company, if construction or fabrication fails to make a weep hole, the QA/QC department rejects the pad and it is cut off, weep hole placed and rewelded.  There are many potentially bad impacts to your PV if violating code requirements.
Parent - - By Duke (***) Date 07-09-2008 01:43
i used to weld large water fittings that got powder coated, and without the vent in the saddle reinforcement, they'd blow up in the oven
Parent - - By ritz (*) Date 07-09-2008 04:19
Hi to all!

I would like to thank you all who gave some technical replies on my question, I always admires this forum especially AWS members for their continous support to anyone.

I just want to know, is requirements for the venthole mentioned in ASME Code? In what specific clause it is stipulated please? COZ Im searching it for a long time but I cant find it til now!! Plase let me know.

If the pad is intended for vessel legs and ventholes is not provided, it is also had a bad impact to a P.V. like if vent holes was not provided on nozzles pad or branch pad.

Any further advise will be greatly appreciated.

Thanks,

Rits
Parent - - By Shane Feder (****) Date 07-09-2008 05:22
Ritz,
B31.3  Section 328.5.4 (g)
ASME VIII  Section UW 15 (d)
Regards,
Shane
Parent - By 803056 (*****) Date 07-09-2008 15:31
Our esteemed member Shane gave just two examples of construction codes that requires the vent holes.

As I stated previously, every ASME pressure vessel or pressure piping code I am aware of has similar requirements.

Best regards - Al
- - By Milibom Date 05-27-2016 16:18
What about if the vent hole is placed at the the crotch of the pad in pipes (spools) construction?
Parent - - By Milibom Date 05-29-2016 23:00
It is possible that someone can explain what is the problem is the vent hole of a reinforcement pad is located at the crotch intead of the side? (ASME B31.3 328.5). Thanks
Parent - By 803056 (*****) Date 05-30-2016 12:51
None that I am aware of.

Al
- By Kfout Date 06-01-2016 15:16
The hole for the reign force saddle. Should this hole be welded closed per 1104 pipeline code? I don't think it should be,just looking for a second opinion.
Up Topic Welding Industry / Technical Discussions / vent hole in reinforcing pad

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