Sterling Hydraulics has extended its range of load control valves. Load control valves, also known as over centre valves, counterbalance valves or boom lock valves, are used to control the movement of a hydraulically supported load as a guard against the consequences of hose failure. In most operations they are connected to the loaded port of an actuator to allow unrestricted input flow via an integral check valve to raise the load.
In many cases, a cross line pilot supply from the actuators other port is connected to the valve pilot port to give a feedback signal that causes the valve to modulate the load, lowering pressure and preventing a runaway situation. The new Sterling Hydraulics E6C1 is a three-port load control valve with the added benefit of being independent of the return pressure in the directional control valve port. It has a special seating arrangement and a chamber that is vented to the atmosphere. This enables the sum of pilot and relief areas to be vented to the atmosphere without the need for a fourth port and associated vent line. This latest load control valve is particularly suited for use with a service line relief valve on the directional control valve, in that the service line relief setting is not additive to the load control valve setting. The E6C1 incorporates a direct acting relief valve for overload protection and a reverse check valve within the body, thus saving space and minimising installation costs.
