Hydraulic check valve
Sterling Hydraulics
A standard two port check valve functions to allow flow in the forward direction yet prevent flow in the reverse direction. They are also referred to as non-return valves.
There are also three port variants available incorporating a pilot-to-open piston that is used to open the check poppet or ball against the opposed pressure to permit reverse flow. A further three port variant is available that operates as a pilot-to-close valve by using a pilot piston to hold the poppet or ball in the closed position to prevent flow in the forward direction. In order to achieve the required opening or closing of these three port valves it is necessary to apply appropriate pilot signal pressure to the pilot piston in relation to the circuit function required.
RANGE CAPABILITY
Sterling check valves are suitable for use up to 420 bar (6000 psi) with flow capacities up to 200 l/min (53 USgpm). Most of the valves are offered in a choice of cracking pressures as governed by a range of available control springs from 0.1 to 25 bar, (1.5 – 362 psi).
