Hi.experts:

anyone has idea on analysis of piping system including axial flow pump resting on spring pad,

the line I am analyzing is going straight from a bottom nozzle of vertical vessel into the top suction nozzle of a axial flow pump thru the horizontal discharge nozzle and forword then goes up into the bottom nozzle of a horizontal shell-tube heater then out the upper nozzole just in line with the bottom nozzle and goes up then return into the vessel in somewhat angle;

I have no idea how to model this pump in CAESAR II,

thanks in advance for any advice

You may wish to consider the pump and its base as a collection of rigid elements and support the base with your springs.
I suggest you size by hand these springs that support your pump rather than have CAESAR II do it since the program may not (because of moments in the line) select the same spring for all the cans under the pump. If you are having CAESAR II size springs (above or below) "Release Restraints" at the pump flanges to separate pump weight (on the base) and pipe loads above the pump.

Thanks Dave, but if I released the restraints (anchor cnode to pump nozzle node) how could I check the nozzle stress with the allowable value from pump vendor?


Sorry for the simple question, I am new fledging in stress analysis, there are still lots of things to learn.

And other question:

as for the vertical vessel if I want to check the nozzle stress with vendor's data, how could I model it, the vessel I am dealing with is vertical with four legs resting on steel structure,the base part is a reversed cone with a DN700 apex nozzle, the other nozzle is tangent with the shell with somewhat angle that is 10deg down and 16.3deg off Z axis;

so,

1. what is the anchor point? the base plate of the supporting legs or the welding point of the legs on the vessel shell?

2. the bottom nozzle can be modeled as a end point of a rigid from anchor point, how about the tagent nozzle?


thanks a lot!

The "Release Restraints" is used only in sizing/selecting the springs. Once the supports are sized and included in the model, all boundary conditions perform as modeled.