Restrictor Check Valves
Lee Restrictor Checks® are miniature 0.187" valves that provide metered flow in one direction and no flow in the other direction. They are functionally equivalent to a check valve in series with a flow restrictor.
Lee Restrictor Checks incorporate a unique feature in their mechanical design. The valve is designed such that the pressure differential across the metering orifice is also located across the valve seat. This design assures that the poppet assembly moves full travel even at low flow rates. Consequently, the valve is less sensitive to silting and contamination than other designs, which may merely locate an orifice upstream or downstream of a check valve. All Restrictor Checks are protected with an integral filter screen.
Directional Flow Controls
Lee Directional Flow Control valves provide metered flow in one direction, and free flow in the opposite direction. Functionally equivalent to a check valve in parallel with a flow restrictor, they are available in four diameters (0.187" - 0.500") with models available for 3,000, 5,000 and 8,000 psi systems.
Lee Directional Flow Controls are available in four different body diameters and are designed for max. operating pressures up to 8,000 psid. The valves are designed such that the full pressure differential across the metering orifice is available to move the poppet full travel. The valves also incorporate filter screens as a means of enhancing contamination resistance. Directional Flow Controls are ideal for timing applications where metering on the outlet in both directions is required. As shown below, two flow controls maintain high back pressure when the actuator is moving in either direction, thus preventing cavitation.
Lee Flosert® flow regulators are pressure compensated flow control valves that provide a constant flow over a wide range of differential pressures. They are available in two diameters (0.281" and 0.500") and a range of flow rates for 3,000 and 5,000 psi systems. A NACE compliant model is also available for pressures up to 8,000 psi.
Lee Floserts® operate by sensing the flow rate in terms of a differential pressure across a fixed orifice. A variable-metering orifice automatically adjusts to keep this pressure, and hence the flow rate constant. Floserts are useful for controlling the velocity of an actuator under variable loads. They can increase the stiffness of a hydrostatic bearing or limit the maximum flow rate to control the speed of a pump or motor.