Re: Re: Butt Welded HDPE Pipe

From: <Pete''s>
Date: Mon May 17 2004 - 20:31:00 EDT

Steve
I've been following the bead situation. I just want to hear how you resolve it. Don't leave us hanging. I'm curious how you are going to get rid of it too.

Pete

• Original Message -----
  From: Steve McKenzie
  To: <a href="/group/PipingDesign/post?postID=VoQFyB6Pvi57t5iF9X6Er2mz0l4AB8DkEYDHhRMRsIXMNlE9Y7y8uK0B4OWPrqJO8O03QucSf4DhLvztlWKy1zVV">PipingDesign@yahoogroups.com</a>
  Sent: Monday, May 17, 2004 2:39 AM
  Subject: RE: [PipingDesign] Re: Butt Welded HDPE Pipe
  

Thanks Tony
I reckon the Re is about 2 million so there you have it. Surprised the
laminar transition would have such an effect. Must check it out. One
day.............

Cheers

Steve

-----Original Message-----
From: Tony Paulin [mailto:tony@paulin.com]
Sent: Monday, May 17, 2004 5:01 PM
To: <a href="/group/PipingDesign/post?postID=VoQFyB6Pvi57t5iF9X6Er2mz0l4AB8DkEYDHhRMRsIXMNlE9Y7y8uK0B4OWPrqJO8O03QucSf4DhLvztlWKy1zVV">PipingDesign@yahoogroups.com</a>
Subject: [PipingDesign] Re: Butt Welded HDPE Pipe

Re: Weld beads and pipeline friction

Hans Bos passed on the following comment I thought might be helpful:

Whether it is important or not depends on the Reynolds number. If flow is
low and the design Reynolds number is in the laminar tubulence transition
the bead could make the boundary layer change to turbulent and then the
friction increases. If the flow is turbulent anyway the bead should hardly
be of importance.

Tony

-----Original Message-----
From: Steve McKenzie [mailto:mechproj@xtra.co.nz]
Sent: Friday, May 14, 2004 4:35 PM
To: <a href="/group/PipingDesign/post?postID=VoQFyB6Pvi57t5iF9X6Er2mz0l4AB8DkEYDHhRMRsIXMNlE9Y7y8uK0B4OWPrqJO8O03QucSf4DhLvztlWKy1zVV">PipingDesign@yahoogroups.com</a>
Subject: [PipingDesign] Butt Welded HDPE Pipe - Friction Loss Due To
Weld Beads

Gents
an HDPE supplier/installer has been asked by his client to debead the
weld inside an HDPE pipeline. The reason given is thought to be
increased pipeline friction due to the weld beads.
The line is 1400mm OD (18m lengths), 56mm wall and the beads are said
to be 10mm high (which seems a little low to me). I did a few rough
sums treating the weld as an orifice plate. The outcome was that the
weld friction loss is less than 3% of the pipe friction loss, which
didnt surprise me.
I am looking for an authoritative (quotable) study/reference on this
subject.
Any leads?
Thanks

Steve

[Non-text portions of this message have been removed]

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[Non-text portions of this message have been removed] Received on Mon May 17 20:31:00 2004