Sizing Control Valves
Valve sizes are usually determined by the CV (Valve co-efficient) CV is determined by the pressure drop(difference between the inlet and outlet pressure) and the flow (GPM) general. Good control is achieved by assuming a 3 to 5 lb pressure drop. For example a flow of 28 gpm will have a CV, based on these assumptions,Â ofÂ CV- 13 to 16. The valve would be between 1 1/4 to 1 1/2 in valve size. If the system is sized right , control valves would be usually .5 in less than the pipe size.
We carry various valve manufacturers such as Belimo, Johnson Controls, Honeywell and Siemens. Most actuators that drive the valves are available in 0-10vdc or o to 20ma. This control signal is usually determined by the temperature control you select.
Yorkland Controls has the experience to size valves correctly for you.