Overcentre valves give static and dynamic control of loads by regulating the flow into and out of hydraulic actuators and will stop runaway in the event of a hose burst.A new 120 litre valve has been added to Integrated Hydraulics' range of Overcentre valves. It has been introduced to compliment the company's existing 30, 90, 140 and 300 litre valves and enables the company to more accurately match valves to specific motion control application requirements. Overcentre valves are designed to give static and dynamic control of loads by regulating the flow into and out of hydraulic actuators.
When installed close to, or within an actuator, these valves will stop runaway in the event of a hose burst or allow thermal expansion relief of the hydraulic fluid where open centre directional control is used.
The NEW valve, the '1CE120', is based upon the company's tried and tested 120 litre balanced and zero differential variants.
It has the spring chamber connected to the valve port, which provides extra stability because of the dampening chamber created behind the poppet.
Pulses produced by bouncing booms etc are eliminated by the highly evolved component design.
In order to minimise its size, the 120 litre capacity cartridge uses a differential area design, whereby the pressure in the cylinder acts over only an annular area on the nose of the poppet.
This reduces the force transmitted to the poppet and consequently the size of the springs required to control it.
This design also provides an excellent flow path, therefore improving a system's efficiency.
It is designed for load induced working pressures to 270 bar, with a maximum relief setting of 350 bar and for flows up to 120 litres/min.
Internal leakage is only 0.3 ml/min.
The adjustment range of Integrated Hydraulics cartridges is particularly wide, simplifying development because one cartridge can be set to give the best results for any given system.
In operation a check section allows free flow into the actuator then holds and locks the load against movement.
The pilot assisted relief valve section will give controlled movement when pilot pressure is applied.
The relief section is normally set to open at a pressure at least 1.3 times the maximum load induced pressure but the pilot pressure required to open the valve and allow movement depends on the pilot ratio of the valve, 3.5:1 for the 1CE120.
The Overcentre cartridge is ideal for mounting directly into a cavity machined in the body of the cylinder, motor or rotary actuator.
The cartridge can also be mounted directly to the ports via a specifically machined body, as part of a Hydraulic Integrated Circuit (manifold block), or contained within a standard line body.
Single overcentre valves are normally used when the load is unidirectional, for example an aerial platform or crane and dual overcentre valves are used for controlling loads in both directions for motor applications or for cylinders going over centre.
Integrated Hydraulics offers an extensive range of Overcentre valves designed to overcome almost any motion control problem that may arise.
Existing valves in this constantly expanding range include: Standard, Balanced, Part Balanced, Counter Balanced and Zero Differential designs.