Safety Valve Setting

[czarlun123]

Good day to all.

Boiler operating at 34 bars, 370 C.
MAWP is 40 bars.

One Safety valve (SV 1) installed at superheater.

Two safety valves (SV 2 and SV 3) installed
at steam drum.

Question: At what specific pressure should
the three valves pop-off?

 

[racookpe1978]

No, you calculate what YOU think it should be, and show us YOUR calculations, and YOUR references.

 

[NovaStark]

Are you doing this research based on a code requirement?

 

[georgeverghese]

Knee jerk reaction would be
SV2 and SV3 should be set at 40barg;
SV1 set pressure should be calculated to be such that the flowing backpressure created at the steam drum will be at no more than 40barg with steam flow at design relief rate through this SV1 at the superheater.

Obviously, the calculated set press for SV1 should be a good margin higher than the max operating pressure of 37barg at the superheater. Would the reason for this posting be that you dont have this margin?