4276584 Excavator Hydraulic Valve for Hitachi ZX200-5B

The part number 4276584 is a genuine Hitachi accessory, which is a direct injection return oil check valve, and its universal number is 4276584. This component is mainly suitable for Hitachi ZAX200, ZAX200-3, ZAX240, ZAX240-3, ZAX230, ZAX250LC-3 and other 20-25 ton medium-sized hydraulic excavators. As a key one-way control component in the hydraulic system return oil pipeline, its installation interface and valve body size (specification: pressure 1.0, 9.0 * 4.2) are precisely matched with the main control valve or hydraulic oil tank return port of the corresponding model.

This product is a straight through threaded connection check valve, which belongs to a type of pressure control valve. Its core function is to allow hydraulic oil to flow in one direction and prevent oil backflow. Its design working pressure is 1.0 MPa, the valve body is compact and small, with a weight of about 0.2kg. The interior usually uses a steel valve core and precision spring structure, relying on hydraulic pressure to open the valve core for one-way communication. When the oil flow is reversed, it quickly closes under the action of spring force and back pressure, forming a reliable seal. This valve is mainly used in hydraulic systems to maintain back pressure in the return oil pipeline, prevent actuator components (such as oil cylinders) from slipping due to their own weight, or prevent hydraulic pumps from emptying. It is a key safety component to ensure system stability and prevent impact.

Installation and inspection: During installation, clean the threaded interface and use appropriate sealant or tape to ensure sealing. Tighten according to standard torque and pay attention to the oil flow direction arrow marked on the valve body. Incorrect installation direction will result in functional failure. Daily maintenance: Check the valve body and connections for oil leakage every 500 working hours. Fault diagnosis: If the system experiences poor oil return, abnormal increase in back pressure, or slow sliding of the actuator, it may be due to the stuck valve core or spring failure of this one-way valve. Remove and clean, check whether the valve core moves flexibly, and whether the spring is broken or permanently deformed.