Explain this

By RANDER

Date 09-09-2008 20:12

If Wt = 1"
Wt X 6 = min spacing (6")

Attachment: Tspc.doc (24k)

By PipeIt

Date 09-09-2008 20:20

So that would be the spacing between two joints?

By RANDER

Date 09-09-2008 20:23

correct

By rockin d (**)

Date 09-09-2008 21:38

Maybe I am not understanding this correctly, but from drawing ,looks like you cant have to welds next to each other ,for example i've been in the position where i had 2 welds 3" apart on a 6" sch. 40 & i had to add 18" of pipe to get away from the other weld. which would be 3 times the diameter of the pipe. I've never heard about the wall thickness thats a new one . Everyday you learn something new

By 65 Pipeliner (**)

Date 09-09-2008 23:16

What are you all using to open this? I can't get it to open. Chris

By shorthood2006 (****)

Date 09-09-2008 23:31

me either

By RANDER

Date 09-09-2008 23:35

Its a MS Word doc(2003) however if you understand the description then you dont need to see the dwg. It is rather quickly done and basic. Sometimes your comp. may download it first to a file and you need to open it from there. Might be called "downloaded from internet" or "internet downloads" depending on your system and/or browser

By jrw159

Date 09-10-2008 00:53

RANDER,
It opened up fine for me but I only opened it to see if it worked. The description was VERY understandable.

jrw159

By sbcmweb (****)

Date 09-10-2008 02:08

I got it too. Took a second though. Not too bad for a junk iron guy :-) S.W.

By PipeIt

Date 09-10-2008 10:05

I too hadn't heard of that method the one you described was more familiar to me then the one I posted.

By Kix

Date 09-10-2008 20:32

I always thought it was diameter as well and not wall thickness, but what you saw by the thread poster supposively came out of a code so that's what goes. What Rander posted is how you would do it.

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

Date 09-10-2008 00:20

Very interesting, PipeIt. Where is that statment written?
Giovanni S. Crisi
Sao Paulo - Brazil

By PipeIt

Date 09-10-2008 10:04

In a specification for a refinery in North America.

By jon20013 (*****)

Date 09-10-2008 10:36 Edited 09-10-2008 14:33

These requirements stem from Engineering Specification, I've not seen Code requirements (not saying they don't exist somewhere) but the reasons are two-fold, to my understanding: 1). Avoid heat affected zones (HAZ) being too close together, and 2) Avoid possible NDE overlaps.

I'm sure there may be other reasons unknown to me but those are what I'm aware of.

I've seen different formulas from different job sites, many use a multiple of the diameter rather than the wall thickness. In my own experience the diameter one is more common.

In some ways, it's kind of similar to some specifications saying that for manufactured seam welded piping (longitudinal welds) being fitted at girth welds, those longitudinal welds must be rotated at 90 degree's from each other when fitting new joints.

EDIT: Correcting typo and adding a little clarity to last sentence.

By Fredspoppy (**)

Date 09-10-2008 13:10

Gents,
The only Code requirement, that I know of, comes from AWS D1.1, Para. 5.22.3.1, Girth Weld Alignment (Tubular), as follows:
"No two girth welds shall be located closer than one pipe diameter or 3ft (1m), whichever is less. There shall be no more than two girth welds in any 10ft (3m) interval of pipe, except as may be agreed upon by the Owner and Contractor".

In my experience, this is the only Code requirement that I have seen.

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

Date 09-10-2008 19:52

PipeIt,
would you mind to tell me who issued the specification?
Thankyou
Giovanni S. Crisi

By Sourdough (****)

Date 09-10-2008 20:35

Give yourself a good gap, and a good land, and do a good job. Whoever is in your ass that much won't even know the difference........