Wet type AC or DC electromagnet. The solenoid valve controls the different working positions of the valve core through electromagnets. When the solenoid is de-energized, the spool is held in the intermediate or end position by spring pressure. Therefore, the working principle of the Xi'an 1130 coal machine reversing solenoid valve is to use wet AC or DC electromagnets. The components of magnets are atoms such as iron, cobalt, and nickel. The internal structure of the atoms is relatively special and they have magnetic moments themselves.