Control Valves Match Size with Application
Control Valves Match Size with Application
(OP)
Here are two good articles about control valve sizing and application. If you deal with control valve selection and sizing then you will find them very informative.
http://www.manufacturing.net/ctl/article/CA192829
http://www.manufacturing.net/ctl/article/CA192621
http://www.manufacturing.net/ctl/article/CA192829
http://www.manufacturing.net/ctl/article/CA192621





RE: Control Valves Match Size with Application
RE: Control Valves Match Size with Application
Double-offset butterfly valves are broken out of the seat by 10 degrees rotation so the friction goes away and control is much improved.
Butterfly valves have a dynamic torque peak at around 70 degrees open, also, and moving past that peak can cause problems as the actuator torque drops off rapidly.
Size your butterfly valve to throttle between 20 degrees open and 60 degrees open. Differential pressure when at max flow should be 1 bar or less, to prevent excessive velocity. Use a rack and pinion actuator (not diaphragm) one size larger than you would normally use, and be sure to use a good positioner and a clamped coupling.
RE: Control Valves Match Size with Application