Relief Valve Sizing Calculator (API 520/521)

Service Type
psig
psig
°F
Required Orifice Area110.8829 in²
Selected OrificeT (26.000 in²)
Rated Capacity11,724.1
Kd (Discharge)0.975
Kb (Back Pressure)1.000
Kc (Combination)1.000
Overpressure10%

API 526 Standard Orifices

OrificeArea (in²)
D0.110
E0.196
F0.307
G0.503
H0.785
J1.287
K1.838
L2.853
M3.600
N4.340
P6.380
Q11.050
R16.000
T26.000