Doesn't tied bellow in between pulsation dampner & compressor discharge transmit vibration axially from positive displacement compressor ?

If P&ID shows untied bellow for vibration isolation, can piping stress modify to tied bellow to avoid pressure thrust ?

regards,
sam

Sam,

I agree with you on both the points.However in my opinion bellows should not be used as it is risky.

Regards

watch for spring supported equipment.
in that case, tied bellows is your only option

Using bellows is a risky choice in the best of times and used with known vibration conditions involves an addition concern of faliure due to cyclic fatigue of the bellows from the equipment. Since when does the Process Engineer specify bellows in a piping system.

Dear Bill,

You are right that metallic bellow is designed for a limited fatigue cycle; not good for vibrating m/c.

But, here, we are mostly talking about non-metallic ambient temperature bellows.

Moreover, we, the stress engineers have not put the same in P&ID. If process engineers own this requirement, its safety will be be their headache, not ours. Also,in such duty the bellows will be changed regularly after a fixed time period as such items will not last the full plant life.

regards,
sam