Usa 801 489 8611 control valve cv tables index table valve model rating characteristic flow table 001 10000 11000 series na equal percent na table 002 10000 11000 series soft seat na equal percent na. For measuring the valve capacity of control valves the coefficient cv or its metric equivalent kv is adopted.
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.
Control valve cv chart. Control valve basics sizing selection introduction a control valve is a power operated device capable of modulating flow at varying degrees between minimal flow and full capacity in response to a signal from the controlling system. Choosing the valve series your next step is to choose a basic valve design to do the job. Calculating control valve cv.
It applies to the factor of the head drop δh or pressure drop δp over a valve with the flow rate q. A control valve may be defined as a valve with a powered actuator that responds to an external signal. With water flow 6 gpm and designed pressure drop 10 psi through a control valve the required flow coefficient c v can be estimated to 2 as indicated in the chart below.
When sizing calculating which size valve is needed for your application a control valve specialist needs to calculate the flow coefficient. Download water c v diagram. In addition to controlling the flow a control valve may be used to shut off flow.
Control valve cv tables 04 index ss004 rev 09 2002 flowserve corporation flow control division tel. A valve cv can be described as the number of gallons per minute gpm at 60 o f 15 5 o c that will pass through a valve with an associated pressure drop of 1 psi. When sizing a control valve the most common approach is to calculate the flow coefficient cv which is a measure of the capacity of the valve body and trim.
Cv 1 x 28 8 1 06 any valve therefore which has a cv of at least 1 06 will extend our cylinder the specified distance in the required time. How do we get value 1 156 conversion factor in formula cv 1 156kv or cv 1 156 q sqrt g delta p. 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.
Example required c v for a water control valve. Control valve cv refers to the flow coefficient of the valve. Cv 25 gpm 1 1 psi 1 2.
The flow coefficient c v for a water control valve can be estimated with the diagram below. Having selected the basic valve design consult the. For a quick guide to valve designs see table 3.
A control valve performs a special task controlling the flow of fluids so a process variable such as fluid pressure level or temperature can be controlled. 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. Control valves may be broadly classified by their function as on off type or flow regulating type.
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.