RE: Re: Minimum distance between Fittings

From: <Parsons>
Date: Thu Mar 27 2003 - 05:07:00 EST

50mm is a good general rule for proximity of Pressure retaining joints, however it is possible to apply a spacing of less than this distance, but the consequences could result in PWHT. Some inspectors will allow distance of 4x thickness of pipe or square root of Dxt, but you should always consult your welding inspector before breaking this 50mm golden rule.

Hope this helps

-----Original Message-----
From: tomcruz55 [mailto:tomcruz55@yahoo.com] Sent: 26 March 2003 19:04
To: PipingDesign@yahoogroups.com
Subject: [PipingDesign] Re: Minimum distance between Fittings

The HAZ width in butt weld joint is very very narrow. So what's with the 50 mm pup piece? We've welded a pup piece less than this to make up for the shoratge in the "short lenght" gate valve without a problem. As long as it pass the NDE and hydro and matl is usitable for service, chances are your fabricated pipe spool will be OK.

For the criteria related to dimesnion of fabricated spool, ive go with the PFI Standard.

• In PipingDesign@yahoogroups.com, "Glenn Dillon" <glenn.dillon@t...> wrote:
  > Hitesh, assume these are butt weld fittings. Fitting to fitting is
  > preferred but where not possible I work on minimum pup spool
  distance of 50
  > mm to allow for weld effected zone and weld efficiency. Haven't
  had any
  > failures yet. With steam, elbows can be highly stressed and its
  best to
  > ovoid short pipe sections and layout distribution to allow fitting
  to
  > fitting.
  >
  > Hope these comments of some help. Best regards Glenn
  >
  > -----Original Message-----
  > From: Ashok Dani [mailto:ashokdani@t...]
  > Sent: Friday, March 22, 2002 4:29 PM
  > To: 'pipingdesign@yahoogroups.com'
  > Subject: [PipingDesign] Minimum distance between Fittings
  > Importance: High
  >
  >
  >
  > > What is the minimum distance required between Bend-Tee or Tee-Tee
  for
  > > Steam
  > > line or as per B31.1?
  > > Thanks in advance
  > > Hitesh
  >
  >
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Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Received on Thu Mar 27 05:07:00 2003