Pressure drop across valve
Pressure drop across valve
(OP)
Hi friends
I am working on a project where I have to calculate pressure drop across a valve.
Data is as follows
Media: Air at 350 deg C
Flow : 26000 CMH
Valve : 600 dia
Valve Kv : 1839 m3/hr-bar
Air is being forced into the valve by an axial fan having discharge pressure of 100 mm of WG
Thanks
I am working on a project where I have to calculate pressure drop across a valve.
Data is as follows
Media: Air at 350 deg C
Flow : 26000 CMH
Valve : 600 dia
Valve Kv : 1839 m3/hr-bar
Air is being forced into the valve by an axial fan having discharge pressure of 100 mm of WG
Thanks





RE: Pressure drop across valve
deltaP = pressure drop [bar]
Q = air flow rate [m^3/h]
rho = air density evaluated @ 350 °C temperature = 0.5667 kg/m^3
RE: Pressure drop across valve
It is necessary to enter the specific gravity "s" of the gas (referred to air in normal conditions, which is assumed to be equal to 1), instead of the gas density "rho". The specific gravity is a pure number and so the formulation given below makes sense from the point of the units of measure.
deltaP = (Q/Kv)^2*s
Being:
s = rho(T=623.15 K)/rho(T=293.15 K) = 0.567/1.207 = 0.47
RE: Pressure drop across valve
I did used specific gravity. Problem is getting the Kv value for the valves as all the data form the supplier is for liquid media.