Control Valves

Valve which limits the maximum circuit pressure, preventing the passage of pressure circuit into the pressure with belebihan load, and controls the torque generated by the motor and hydraulic cylinders. Relis simple valve (operation described in the basics of hydraulic module) is used when excessive load protection is required because this katuprelif react to add pressure quickly. However, the valve reliefs have a very high level override (the difference between cracking pressure with full flow pressure), therefore, to control the operating pressure of the circuit, then use a complex valve along with a small deposit of normal use. Type a balanced piston valve reliefs operates with very little storage.

Balanced piston type relief valve
The main spool is pressed against the main valve seat along with the initial pressure of the construction by using the main spool spring. Pilot valve is pressed against the valve seat pilot through the pilot spring, the pressure can be set via the handle.

If the actuator is affected by the load and the oil pressure in the A, then change the oil pressure pilot valve to the right after passing through a choke to the section B. When the oil pressure exceeds spring pressure pilot, the pilot valve will open and allow the oil to flow through the A and b continue to C to D and E. If the load increases again, then the choke which is housed in the A and B be lifted, causing a pressure difference between A and B. If this pressure difference exceeds the style of play spool spring, the main spool will go up, and The main valve seat will be open, and let the high pressure oil flows into the tank circuit E. Then, prevented the increase in pressure A.

Figure 4.78 valve reliefs

Pressure Reducing Valves
This valve is used to reduce the pressure in a series of more than uatama circuit. This is normally called the valve is open.

 

Figure 4.79 Pressure Reducing Valves

Valve series
These valves are used to control the function of the hydraulic actuator series with the circuit pressure. This valve is constructed together with valve reliefs but has a spring chamber which flowed separately into the reservoir. This valve also has an integral check valve backflow. This valve is a normally closed valve.

Figure 4.80 pressure sequence valve

Balancing Valves
Way valve that prevents the actuator far ahead because of the load speed of use within a controlled and maintained. This valve works by providing resistance to flow until a preset pressure is reached. Balancing valve has an integral check valve alira inverting.