YB60001816 VALVE PILOT For HITACHI ZX120-5G 4BG1

The pilot valve is an auxiliary valve used to operate the control mechanism in other valves or components. It has a relatively small input signal and can accept a variety of input methods, such as manual, electric, hydraulic and pneumatic. The pilot valve is usually composed of electromagnet for wet valve, valve core, transmission plunger, valve sleeve, thimble rod, steel ball, steel ball seat and return spring. The pilot valve itself is often a small-sized control valve, mostly a pressure control valve. The working principle of the pilot valve is to control the main valve or the secondary valve based on the input signal. It controls the main valve or the secondary valve according to the input signal by forming a pilot control liquid bridge with a fixed liquid resistance. The flow rate of the pilot valve is generally between 1 liter/minute and 3 liters/minute, and the specific flow rate depends on the actual needs. When power is cut off, under the action of spring force and gravity of the spool, the valve stem is reset, the pilot hole is closed, the main spool moves downward, the main valve port is closed, the pressure in the upper cavity of the solenoid valve increases, and the fluid pressure pressurizes the main spool to ensure better sealing.

Pilot Valve is a kind of safety valve, which consists of a main valve and a pilot valve, and is mainly used to control the safety protection in high-pressure environment. The pilot valve controls the opening and closing of the main valve by sensing the pressure signal of the system. It has the characteristics of sensitive opening, high seating pressure and good sealing, and is widely used in the fields of oil and gas, chemical industry, electric power, metallurgy and city gas. The working principle of the pilot valve is to sense the controlled pressure signal based on the pilot valve. When the pressure in front of the safety valve is lower than the set pressure, both the pilot valve and the main valve are closed without leakage. As the pressure approaches the set pressure, the pilot valve opens, the main valve opens quickly, and the medium is discharged; When the pressure returns below the set pressure, the pilot valve is closed and the main valve is also closed. The main features of the pilot valve include high operating sensitivity, high seating pressure, double sealing structure, high back pressure discharge capacity, long service life and stability. It adopts sleeve piston structure, which has the characteristics of high precision, high repeatability and fast seat return, and can be adjusted online, which is convenient for operation and maintenance

The main function of the pilot valve is to control the hydraulic system or pneumatic system accurately by controlling the main valve or the secondary valve. It uses a small flow to control a large flow, and uses a small control pressure to control a large flow of fluid or gas, thus realizing the precise adjustment and safety protection of the system. The characteristics of the pilot valve include: the pilot valve is usually used to control small flow, and the main valve with large flow is accurately controlled through this small flow. Can accept manual, electric, hydraulic, pneumatic and other input methods. A variety of pilot valves can form a modular structure, which is convenient to choose different functions according to actual needs. The pilot valve itself is usually a small-sized control valve, mostly a pressure control valve.