The solenoid coils are fixed with nuts for easy replacement. The hydraulic solenoid valve parts assembly utilizes this force to overcome the spring force and the liquid force, to opens or closes the corresponding flow channel. The armature sleeve assembly converts the magnetic force into a pulling force or thrust force in a magnetic field. The solenoid coil converts the input current into a magnetic field. The solenoid valve is generally composed of three parts: solenoid coil, solenoid piston assembly and solenoid valve parts assembly. For simplicity and ease of comparison, the graphical symbols do not distinguish between electrically and electro-hydraulic valves. In general, only the two-way type and the three-way valve in the hydraulic solenoid valve have a pilot type that is electrohydraulic control, and the other types are direct-acting spool valves, that is, electric control. However, there are also individual varieties that use softer seats in order to meet the strictly requirements for internal leakage in certain applications.įrom the internal structure, the hydraulic solenoid valve can be divided into direct-acting and pilot differential. The valve spool and spool seat are generally made of steel and hardened to achieve long life. Hydraulic solenoid valve, from the point of view of the structure of the main valve spool, only two position, two-way and two position and three-way seat valve are spool with seat valve, the other are all spool valve. The 2/2-way hydraulic solenoid valve type has a much more connected form in the de-energized condition than the modular solenoid valve. Hydraulic solenoid valve can open and close one or more flow channels by energizing and de-energizing the solenoid, usually there are modular hydraulic solenoid valves and cartridge solenoid valves installed in the hydraulic system or equipment.