Hi,

In the pump suction line analysis, as per stress philosophy I have to perform nozzle disconnected case (3 mm displacement is allowed). I generally know that in WNC case keeping Anchor (with CNODE) stiffness to zero, we can perform this case. Please correct me if I am wrong.

One more clarification I need is, if we keep the anchor stiffness to zero, it will consider the same for all load cases including WNC case. Is there away that only in WNC case we can keep Anchor stiffness to zero, not effecting the remaining load cases. Please help me.

Thank you in advance

Hi Suresh,
Nozzle disconnected means it is not bolted to pump nozzle and thus has six degrees of freedom ie X,Y,Z, RX, RY,RZ.So no need for load check.
If you want to check displacement check it using maximum displacement .

1. It is correct.
2. It is not possible, you will have to do this in a separate file.

@learner2011 - 3 mm it is about the vertical deflection of the piping (flange) when disconnected


Regards,

Dan,
Is my approach correct or one given by Suresh

You are right also that being disconected it is pointless to check for nozzle load. But what Suresh (or his company standard) want is that the suction line is balanced as CG (in order to minimize dead loads on pump nozzle), so to check the deflection at the disconnected end. If this is his company approach then the way it can be done is the way described.


If you want my opinion on this approach, here is my view.

It is ok, unless.........

Unless what? Unless somebody will place a support very close to the nozzle. It will solve the deflection, but can do some harm to the pump.

Best regards,

Thank you so much, Danb.

Regards,
suresh

Suresh,

Also , do ensure that the lateral displacements at pump flanges are not higher as this may result in difficulties during bolt-up.

There may be cases where you may end up with proper alignment in vertical direction but may have higher displacements in lateral directions during alignment check.This is usual trend for top discharge /suction pumps.

Keep Smiling,

SJ

Smile is the best give you may ever give.