Dear All,

I need some advise on the load case.

I have 6 units of PSV connecting to flare header from 2 units of booster compressor. 3 units of PSV for each unit of booster compressor.

To my understanding, reaction force of PSV occur during PSV "pop up". In such condition, there is relieving temperature and relieving pressure. I assume that all the 6 units of PSV will not "pop up" at the same time. The most critical condition will be that 3 units of PSV from one unit of booster compressor "pop up" at the same time.

Therefore, my load case will be as below:

T1 = Operating Line Temperature
T2 = PSV 1 Relieving Temperature
T3 = PSV 2 Relieving Temperature
T4 = PSV 3 Relieving Temperature
T5 = PSV 4 Relieving Temperature
T6 = PSV 5 Relieving Temperature
T7 = PSV 6 Relieving Temperature

P1 = Operating Line Pressure
P2 = PSV1 Relieving Pressure
P3 = PSV2 Relieving Pressure
P4 = PSV3 Relieving Pressure
P5 = PSV4 Relieving Pressure
P6 = PSV5 Relieving Pressure
P7 = PSV6 Relieving Pressure

F1 = PSV1 Reaction Force
F2 = PSV2 Reaction Force
F3 = PSV3 Reaction Force
F4 = PSV4 Reaction Force
F5 = PSV5 Reaction Force
F6 = PSV6 Reaction Force

Load Case

L1 = W+P1+T1 (OPE)
L2 = W+P2+T2 (OPE)
L3 = W+P3+T3 (OPE)
L4 = W+P4+T4 (OPE)
L5 = W+P4+T5 (OPE)
L6 = W+P6+T6 (OPE)
L7 = W+P7+T7 (OPE)
L8 = W+P2+T2+F1 (OPE)
L9 = W+P3+T3+F2 (OPE)
L10 = W+P4+T4+F3 (OPE)
L11 = W+P5+T5+F4 (OPE)
L12 = W+P6+T6+F5 (OPE)
L13 = W+P7+T7+F6 (OPE)
L14 = W+P1 (SUS)
L15 = W+P2 (SUS)
L16 = W+P3 (SUS)
L17 = W+P4 (SUS)
L18 = W+P5 (SUS)
L19 = W+P6 (SUS)
L20 = W+P7 (SUS)
L21 = L1-L14 (EXP)
L22 = L2-L15 (EXP)
L23 = L3-L16 (EXP)
L24 = L4-L17 (EXP)
L25 = L5-L18 (EXP)
L26 = L6-L19 (EXP)
L27 = L7-L20 (EXP)
L28 = L8-L2 (OCC) F1 with operating condition
L29 = L9-L3 (OCC) F2 with operating condition
L30 = L10-L4 (OCC) F3 with operating condition
L31 = L11-L5 (OCC) F4 with operating condition
L32 = L12-L6 (OCC) F5 with operating condition
L33 = L13-L7 (OCC) F6 with operating condition
L34 = L15+L28 (OCC) Scalar combination
L35 = L16+L29 (OCC) Scalar combination
L36 = L17+L30 (OCC) Scalar combination
L37 = L18+L31 (OCC) Scalar combination
L38 = L19+L32 (OCC) Scalar combination
L39 = L20+L33 (OCC) Scalar combination
L40 = L34+L35+L36 (OCC) Absolute combination
L41 = L37+L38+L39 (OCC) Absolute combination

Please kindly advise me.

Thank you so much

Regards
Loh