Control valve cv refers to the flow coefficient of the valve. The valve coefficient cv in imperial unit the number of us gallon per minute of water at 60 f that will flow through a valve at specific.
M3 h for a pressure drop of 1 psi 1 bar across a flow passage flow coefficient.
Online cv calculation for control valve. Calculating the flow rate from the cv value requires complex calculations. The use of this flow coefficient c v calculator leads to a standard calculation to compare valve capacities. Calculation example of the flow through a valve of coefficient cv.
For measuring the valve capacity of control valves the coefficient cv or its metric equivalent kv is adopted. Online cv calculation for control valve. For a specific control valve flow coefficient cv kv is determined experimentally by control valve manufacturers and you can found it in manufacturers technical specifications.
When sizing calculating which size valve is needed for your application a control valve specialist needs to calculate the flow coefficient. Such as the renault number reynolds number flow rate flow the shock choking the involved joints in pipes fitting and the other by the values of these. If flow capacity required is known and valve selection is desired to calculate cv with the following formulaes and select appropriate valve from.
The density of water at 15 c is 999 13 kg m 3. It applies to the factor of the head drop δh or pressure drop δp over a valve with the flow rate q. For a quick guide to valve designs see table 3.
It is water at 50 c. Calculating control valve cv. The flow coefficient for a control valve which in full open position passes 25 gallons per minute of water with a one pound per square inch pressure drop can be calculated as.
This is our valve c v calculator. They express coefficient cv kv as the flow rate of water in g p m. 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.
M3 h for a pressure drop of 1 psi 1 bar across a flow passage flow coefficient. Cv 25 gpm 1 1 psi 1 2. Process control instrumentation and process control systems design and documentation.
How do we get value 1 156 conversion factor in formula cv 1 156kv or cv 1 156 q sqrt g delta p. Control valve cv calculation in deciding the size of the control valve that port size we need to calculate the cv value of the process calculated cv by calculating cv has educated more than 50 years which is involved in. Gases and compressed air air lng lpg and other common gas properties pipeline capacities sizing of relief valves.
C v flow calculator. They express coefficient cv kv as the flow rate of water in g p m. What is the flow through the valve.
For a specific control valve flow coefficient cv kv is determined experimentally by control valve manufacturers and you can found it in manufacturers technical specifications. Control valves control valve terminology bodies trim flow characteristics cv and kv sizing noise actuators and positioners. C v calculator for valve sizing.
The instrumentation on the line show that the pressure drop through the valve is 0 1 bar. A control valve has a cv of 5.