RE: (PipingDesign) Pump Nozzle loads

From: <Roger>
Date: Mon Sep 17 2001 - 09:53:00 EDT

From a mechanical equipment stand point (and following ongoing maintenance) it is best not to put any loads on the pumps etc. Piping strain is one of the banes of the maintenance trades in pump life. And there are very few tradesmen and engineers at the plant levels who have access to the piping design information in order to determine how to fix it. There is a lot of guess work. If you can design away from it, the field personnel will try to 'fix' the suction/discharge piping into position so as to have zero loading on the pumps.

-----Original Message-----
From: PipingDesign@yahoogroups.com at -INTERNET Sent: Sunday, September 16, 2001 02:02 PM To: PipingDesign@yahoogroups.com at -INTERNET Subject: RE: [PipingDesign] Pump Nozzle loads

> Any
>suggestions from dear and experienced membsers to tame
>this loads ( forces and moments)within allowable?
Some of the problem may be overly-conservative assumptions of the stiffness of the pump mounting. Assuming that a pipe is rigidly fixed, does indeed result in high forces, but in fact truly rigid fixity is rare, if it even exists. It's always a good idea to back check the effects of your piping endloads on the pump or anchorage to see if the assumed support condition truly exists, especially if you're getting very high loads.

As an associated point, the assumption of regid fixity may also affect the piping analysis. I've had to deal with piping systems where a light piece of equipment was taken as a point of fixity, when in fact there was very little support provided to the piping system. There was good reason to believe that the piping system would have been overstressed as a result.

Christopher Wright P.E. |"They couldn't hit an elephant from <a href="/group/PipingDesign/post?postID=w-2H-hJqcCv3Po6fS7S_yhPxw3s-zn46DzIa0NJG1h-T2sabynkZ_2ONGXgF35cRhJD-c-nnx9ThqbWsOw">chrisw@skypoint.com</a> | this distance" (last words of Gen.

___________________________| John Sedgwick, Spotsylvania 1864)

<a href="http://www.skypoint.com/~chrisw">http://www.skypoint.com/~chrisw</a>

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Your use of Yahoo! Groups is subject to <a href="http://docs.yahoo.com/info/terms/">http://docs.yahoo.com/info/terms/</a> Received on Mon Sep 17 09:53:00 2001