Dry seal gas pressure determine

[M Arshad]

Hi dears,
I am working on single stage centrifugal compressor. I m studying dry gas seal system. I am confusing on the pressure supplied to primary seals on both suction and discharge side. Suction pressure is 9.5bar and discharge pressure is 12.6. H2s gas is taken from discharge of compressor and supplied to primary seals after filtration through seal gas filters and flow is controlled through an orifice plate.
I want to know how can i determine reference pressure??
Thank you in advance

 

[georgeverghese]

What do you mean by reference pressure ?
Seal gas filters will be operating at compressor discharge pressure minus a bit, since the orifice plate will be downstream of the filters - pls check. If so , the seal gas filters should be selected with minimum compressor normal operating discharge pressure in mind also.