Hydraulic balance valve construction machinery parts CBCA-LBN

The working principle and function of the relief valve

1, the relief valve constant pressure overflow effect: in the quantitative pump throttling regulation system, the quantitative pump provides a constant flow. When the system pressure increases, the flow demand will decrease. At this time, the relief valve is opened, so that the excess flow flows back to the tank, to ensure that the relief valve inlet pressure, that is, the pump outlet pressure is constant (the valve port is often opened with pressure fluctuations).

2, safety protection: When the system is working normally, the valve is closed. Only when the load exceeds the specified limit (system pressure exceeds the set pressure), the overflow is turned on for overload protection, so that the system pressure is no longer increased (usually the set pressure of the relief valve is 10% to 20% higher than the maximum working pressure of the system).

3, as a unloading valve used as a remote pressure regulator:

A high and low pressure multistage control valve is used as a sequence valve to generate back pressure (string on the return oil circuit).

The pilot relief valve consists of two parts: the main valve and the pilot valve. Pilot valves are similar to direct-acting relief valves, but they are generally cone valve (or ball valve) shaped seat structures. The main valve can be divided into one concentric structure, two concentric structure and three concentric structure.

On the main valve, there is a clear difference from other relief valves. The main relief valve of the excavator with the function of strengthening will have more than one pilot pipe. The problem of the main relief valve is generally that the internal spring is broken or failed, the valve core is worn, and the whole operation is weak and the pressure cannot be established