ValveCoef_Inc_ISA75_CL
The procedure ValveCoef_Inc_ISA75_CL uses the detailed sizing relations laid out in ANSI/ISA-75.01.01 (IEC 60534-2-1 Mod)-2007, "Flow Equations for Sizing Control Valves" to determine the valve coefficients (C_v and K_v) for a valve with incompressible flow given the flow conditions, geometry, valve type, pressure drop and required flow rate. A simpler method is programmed in ValveCoef_Inc_CL. The values of the liquid pressure recovery factor (F_L), valve style modifier (F_d), and pressure differential ratio factor (x_T) depend on the valve style and trim and can be found in Table 2 of the standard.
ValveCoef_Inc_ISA75_CL(F$,T_1,P_1,P_2, Q, D, D_1, D_2, F_L, F_d, x_T, Conc: K_v, C_v)
Inputs:
F$ fluid
T_1 inlet temperature (C, K, F, or R)
P_1,P_2 inlet and outlet pressures (kPa, Pa, bar, MPa, atm, or psi)
Q flow rate (m^3/s or ft^3/min)
D valve diameters (m or ft)
D_1, D_2 inlet and outlet tube diameters (m or ft)
F_L liquid pressure recovery factor (-), depends on valve style
F_d valve style modifier (-), depends on valve style
x_T pressure differential ratio factor (-), depends on valve style
Conc concentration (%), only required if fluid is a solution (brine)
Output:
K_v SI valve coefficient (-), returned as dimensionless but technically this is measured as m^3/hr of water passing through a valve with a pressure drop of 1 bar
C_v English valve coefficient (-), returned as dimensionless but technically this is measured as gpm of water passing through a valve with a pressure drop of 1 psi
Example:
$Load Component Library
$UnitSystem SI Mass J Pa K
F$ = 'Acetone'
T_1 = 320 [K]
P_1 = 500e3 [Pa]
P_2 = 300e3 [Pa]
Q = 0.05 [m^3/s]
D_1 = 0.05 [m]
D_2 = 0.05 [m]
D = 0.04 [m]
F_L = 0.9 [-]
x_T = 0.7 [-]
F_d = 0.48 [-]
CALL ValveCoef_Inc_ISA75_CL(F$,T_1,P_1,P_2, Q, D, D_1, D_2, F_L, F_d, x_T, 0 [%]: K_v, C_v)
{Solution:
K_v = 36.6 [-]
C_v = 42.31 [-]
}