What is it though that you're actually trying to do?
At current conditions:
DP across the second orifice is 2.8 Kg/cm2_g. I am trying to calculate flow in this case.
I am also not sure what 'restriction(choke)' mean. I am only assuming it means that choked flow.
Assuming it not choked flow, D/L ration is 0.009. Hence usual orifice formula wouldn't apply.
I do not have drawing of the orifice. Data sheets mentions ' It is a restriction(choke) type venturi...
My understanding is that Pcrit is property of service gas at given temperature and pressure. Pcrit is not a function of orifice dimensions.
Also, since it is restriction orifice, I am assuming no pressure recovery.
I have two orifices ( Capillary type ) in series in H2 service at 30 kg/cm2_g and 40 Deg C. Line size is 0.75 inch. As per their datasheet
1st Orifice: Do = 0.51 mm & L = 50 mm ; Pressure drop at Max flow : 6.89 kg/cm2_g
2nd orifice: Do = 0.51 mm & L = 50.83 mm ; ; Pressure drop at Max flow ...
