Dear all
Some time back I was working with client who makes typical plants. There were 3 water pump discharge line ( see attach sketch ). I tried with one tied rubber bellow at pump discharge nozzle but could not manage pump nozzle allowable load . Line design temperature was 45 deg C. So I suggest one more tied rubber bellow at vertical portion of line ( see attached sketch , note additional rubber bellow ).
My client was reluctant to accept my design since they continuously installed typical pump line with one tied bellow each at pump discharge nozzle. We force them to accept new proposal since we could not produce a nice stress report with only one tied bellow per each discharge line.

Now question do we really require that additional bellow ?
I have worked with another very established design company who put ( rest +
Guide + axial stop ) support just after tied bellow same location where I presently marked rest +guide support in attach sketch.
I know we can not put pump nozzle , tied bellow reducer & then axial stop support in same line.
Caesar report also show tremendous high axial load in this case.
But new client they are quiet confident that pump will wotk fine with same configuration since so many typical line they already installed is working fine.

One point I am thinking now. It is a simple cooling water discharge line. No practical problem I am also expecting with that configuration even though I can not make a good caesar output report . I definitely will not do that thing for pump which is working with high temperature.

Now to prepare stress report I am making following assumption.
1) Very small axial deflection bellow can absorbed , may be by laterally deflection. ( no much theoretical )
2) While modelling tie rod in caesar I am putting X restraint with gap 1 mm. ( pump nozzle is in X direction )
3) Since 1 mm restraint gap caesar will show pressure thrust I remove effective Id of bellow.

That means I am considering a tied rubber bellow which can absorbed very small amount of axial movement also. Calculated axial movement is also less than 0.3 mm between pump discharge nozzle & first axial stop support.

So I like to know what is the opinion of Expert . Specially I request “JOUKO “ to put some light on the issue.