Hydraulic logic valve symbols

Logic valves come in many different forms so we've only tried to cover a few of the main types here.

Top left is a directional control cartridge poppet valve with a 1:1 ratio, as shown by the straight nature of the spool/poppet body.

Top right is a directional control cartridge poppet valve with an area ratio =< 0.7

Bottom left is a directional control cartridge poppet valve with an area ratio > 0.7

Bottom right is a directional control cartridge poppet valve with an area ratio =< 0.7 but with a damped / throttle nose.

Learn more about logic valves