[23] Circuit symbols for flow control valves

A distinction is made in flow control valves between types which are affected by viscosity and those which are unaffected. Flow control valves unaffected by viscosity are termed orifices. A 2-way flow control valve consists of restrictors, one adjustable restrictor which is unaffected by viscosity (orifice) and a regulating restrictor (pressure compensator). These valves are represented by a rectangle containing the symbol for the adjustable restrictor and an arrow to represent the pressure compensator. The diagonal arrow through the rectangle indicates that the valve is adjustable.