Recirc pump Analysis

Posted by: egcallis

Recirc pump Analysis - 09/02/11 03:18 PM

We have several recirc pumps that have large loads being placed on the discharge and suction nozzles. The client wants the pumps put on springs. How do I model the pump to get the combined loads/displacements at the two nozzles?
Posted by: corne

Re: Recirc pump Analysis - 09/03/11 07:49 AM

Personally I would never place a piece of equipment on springs if piping loads are too high.
If I see your attachment I think you can get the nozzle loads correct by placing/changing supporting. However I only see a very small piece of the piping system of course.
For the combined loads in 1 node you need to use rigids and maybe also c-nodes. The use of c-nodes depends on whether or not you have modelled the pomp with rigids.
Are you really sure you have to check the combined nozzle loads?
Posted by: Farhad

Re: Recirc pump Analysis - 09/04/11 10:03 AM

Dear Egcollis,

Specify pump base node with an anchor, then use 2 RIGIDS from base node to suction and discharge nodes. Now here is your pump with 2 nozzles. Model suction and discharge lines from these nodes. You may also use anchor + CNODE to attach pipes to rigid elements. Then use API 610 pump analysis in C2 to check pump loads.
Posted by: Surjeet_Kumar

Re: Recirc pump Analysis - 09/05/11 03:33 AM

Dear Egcollis,

I think you can control your piping loads by putting spring in discharge line near nozzle in horizontal spool and change first support in suction nozzle to spring.
Posted by: egcallis

Re: Recirc pump Analysis - 09/12/11 06:34 PM

Attached is the pump in question. I can compute combined vertical spring stiffnesses and equavlent bending stiffness, but how do I deal with horizontal stiffnesses?
Posted by: Bob Zimmerman

Re: Recirc pump Analysis - 09/16/11 05:45 PM

Rule of thumb for simple springs shown is K vert = K horiz, but talk with (Google) Amber / Booth springs in Houston, Texas and see what they say.