4 replies to this topic

[demyx]

Hi everyone,

 

I should size a PSV for blocked outlet on compressor discharge.

 

Our internal standard says to use maximum suction pressure (in this case it would be suction vessel design pressure) and set pressure of PSV as discharge condition in order to evaluate flowrate from compressor curve.

 

I don't have any compressor curve, so how can I evaluate relieved flowrate?

 

 

Thank you.

Edited by demyx, 11 December 2019 - 08:03 AM.

[Bobby Strain]

What type is the compressor? If it is a centrifugal machine you must have a curve. And the condition at the suction depend on the service.

 

Bobby

Edited by Bobby Strain, 11 December 2019 - 07:34 PM.

[demyx]

Yes, it is a centrifugal compressor.

 

So I can't estimate the relieved flowrate if I don't have any curve.

 

Thank you Bobby.

[PhilippM]

Yes, it is a centrifugal compressor.

 

So I can't estimate the relieved flowrate if I don't have any curve.

 

Thank you Bobby.

I don't think you can determine the flowrate for the conditions you described without the curve. Unless you want to find the curve by reverse engineering: Why don't you ask the vendor?

[SawsanAli311]

Consider a margin on top of the rated flow taking into account whether your compressor is on VSD control. Considering that compressor can speed up, we usually consider the relieving flow rate as a margin on top of the rated flow or estimate in HYSYS simulation what is the maximum flow rate through the compressor with the fixed maximum power limitation.