PSV sizing for gas blowby case

[kath]

Hi ...
can anyone share how to determine the relieving rate for gas blowby case ?

[padua]

Kath,

First determine all the control valves flowing into that vessel, then you need to determine
which is the maximum flow from each individual control valve, which valve gives the highest
flowrate at maximum Cv, from there you only choose one control valve giving you the highest
flow at that maximum Cv(valve should be 100% open), the rest of the control valves should be
added to the maximum control valve flowrate at normal condition, you should get the control
valves datasheets from the vendor.

[padua]

kath,

try get hold of API 521, and look up Gas Blowby.

Padua.

[Nabilia]

API Standard 521 5th Ed. Jan. 2007 - Pressure-relieving and Depressuring Systems - ISO 23251.pdf 4.001 MB

[link Point to another website Only the registered members can access]
API Standard 521 5th Ed. Jan. 2007 Addendum 2008.pdf 0.283 MB

[link Point to another website Only the registered members can access]