Re: [Fwd: [STM] Steam line intermediate anchor]

So as to clarify this layout.... The lines enter and exit manholes where there are slip type EJs located. After leaving the side of the manhole the line is immediately buried???? Or is it in a casing pipe ??????

If the line is buried it will develop whats called and described by some as a virtual anchor... the ground will develop local plastic deformations but in essence will restrain the pipe.

A chase pipe is another matter altogether.

• In PipingDesign@yahoogroups.com, Paul Bowers <pbowers@p...> wrote:
  > Forwarded from the Steam list, maybe someone here has some insight:
  >
  > -------- Original Message --------
  > Subject: [STM] Steam line intermediate anchor
  > Date: Tue, 21 Jun 2005 07:59:17 -0500
  > From: Gephardt, Tim <gephardtt@m...>
  > Reply-To: steam-list@l...
  > To: <steam-list@l...>
  >
  > To all,
  >
  > We have a 16", 60 psig steam line constructed in 1955, and it
  was
  > placed in a chase type system with slip style expansion joints in
  > concrete manholes to compensate for thermal expansion. According
  to the
  > original design documents there were no intermediate anchors
  installed
  > on runs of steam piping where expansion joints are on either end of
  the
  > run. Not having an intermediate anchor would allow the steam
  piping to
  > grow in the path of least resistance and if the expansion joint
  travel
  > was not oversized enough to compensate for the growth of the entire
  run
  > of piping, the piping would then bump off of the limit stops inside
  one
  > expansion joint before the piping grew in the other direction. I
  may
  > have this situation as when this line was shut down and I was
  inspecting
  > for an expansion joint replacement, I noticed that an expansion
  joint
  > had only contracted about a half an inch, where it should have
  moved at
  > least a couple of inches. This would indicate either a broken
  > intermediate anchor or a complete lack thereof, from the initial
  design.
  > I was just curious if any one else had encountered this type of
  design
  > on older lines? I will be doing an exploratory dig at the mid
  point of
  > this line coupled with some abatement to search for a broken
  anchor, or
  > if there is not an anchor, establish one after I make sure my
  piping is
  > not offset too far one direction or the other.
  >
  > Thanks,
  >
  > Tim Gephardt
  > Senior Staff Engineer
  > University of Missouri - Columbia
  > Energy Management
  > 417 South 5th Street
  > Columbia, MO 65211-2030
  > Phone: (573) 884-9339
  > Fax: (573) 882-6793