Position of Pipe Longitudinal Seam Weld 1

[carlomaderazo]

Hi,
May I know where can I find in ASME B31.3 the minimum longitudinal weld seam distance for piping and what should be their locations?

Thanks

 

[BigInch]

Min length as long as the pipe. Located between OD and ID.

Seriously, I don't think you'll find these questions answered in B31.3.

"I am sure it can be done. I've seen it on the internet." BigInch's favorite client.

"Being GREEN isn't easy." Kermit

http://www.youtube.com/watch?v=hpiIWMWWVco

http://virtualpipeline.spaces.live.com

 

[dcasto]

I'd keep the seam between: 30 and 60 degrees or 210 to 330 degrees. for the field hands that means between 1 o'clock to 5 o'clock or 7 o'clock and 11 o'clock. For ex Marines thats when the little hand is between the 1 and 5 or from the 7 to 11.

 

[stanweld]

B31.3 does not address placement of longitudinal seams or staggering thereof in service.

 

[MJCronin]

All,

I have heard of this bizarre "placement requirement" for weld seamed pipe only once before.

The only application that this makes sense (to me)is in sulfuric acid service, where there is an erosive/corrosive attack within the pipe at the 12 o'clock position. (This is also called hydrogen grooving)

Unfortunately, this kind of knowledge spreads quickly amongst "pipers" and pretty soon all piping is configured this way.

I agree that B31.3 makes no mention of this.

Anybody else have any experience with this ?

-MJC

 

[kacarrol]

Thanks for the insight on the hydrogen grooving. I had not heard of that before (but I haven't dealt with acids before).

A quick search turned up this article:

http://www.environmental-expert.com/resulteacharticle.aspx?cid=1218&codi=13342

Neat stuff.

 

[PAN]

For pipe fittings (e.g. elbows, tees, etc.)with longitudinal seam, we may not be able to avoid 12 o'clock position...