Cv Calculation For Gas Metric. This is psig (gauge pressure) plus 14.7 (atmospheric pressure) It allows you to calculate the flow or c v (flow coefficient) to make the relationship visible between the pressure drop (the difference in pressure between two points in a network transporting a liquid or gas) and the flow rate.
This reduces the calculation as follows. The larger this value, the higher the flow rate through the valve will be at a given pressure drop. Convert from cubic feet to kilowatt hours (multiply by 31.6586).
= mass flow in lbs/min r = universal gas flow constant (1545 ft lbf/(lb mol)(°r)) divided by m.w.
Due to this density reduction the gas is accelerated up to a higher velocity than the one reached by an equivalent liquid mass flow. In effect this means that the fluid data for the fluid zone associated with the control valve must be defined for the approximate pressure condition at the outlet. G = specific gravity (air=1.0) t = flowing temperature absolute (ºf + 460) q = 34.3 cv p g the rate of flow of a liquid or gas through a valve depends upon numerous factors such as T = gas temperature in °r (°f + 460) z = compressibility factor assumed at.
