1 reply to this topic

[roshimessi]

Dear friends

in my project client wanted to use one of their existing vessel as test separator from  their other project to this project, and they wanted from us to review

this vessel is three phase separator and has been made with operating pressure of 55and design pressure of 75 bar.

they wanted to use in the system with operating pressure of 30barg and design pressure of 40 bar,

i have two concern about :

1- about psv

2- control valves

does it need to change the psv and using the psv with 40 barg, or existing psv with 75barg is enough and can cover the all scenarios such as fire, if existing psv is enough ,is it applicable to use this psv(for any scenario)

for control valves:

 I think the control valves shall be changed

because the operating pressure has been changed

 

 

thanks

rosshi

[fallah]

rosshi,

 

You can change the operating pressure of a vessel but vessel design pressure remain unchanged. Then, even with lack of adequate info, appears just by lowering the operating pressure the credible scenarios and relevant relief loads not to be changed, hence existing psv can handle the new conditions without any safety issue.

 

About the control valves again with lack of even a simple sketch, you should consider relevant design basis and turndown. If new operating conditions causes the unit would go below turndown; then the control valves might need to be replaced with new ones.