The solenoid valve is a commonly used component in the industrial control field for the on-off conversion of fluids. It belongs to the actuator and is mostly used in electromechanical systems and precise flow control fields. During the operation of solenoid valves, due to moist air and corrosive gas corrosion, the mechanical strength, heat conduction and heat dissipation effect of the solenoid valve coil are reduced, which affects normal operation and even leads to a decrease in insulation level, causing accidents. Therefore, it is very necessary to dry the coil in the solenoid valve. The commonly used drying methods for solenoid valve coils include the following: microwave drying method; Vacuum drying method Infrared drying method Conductive drying method Convection drying method.

At present, vacuum drying is commonly used for electromagnetic coils. There are many pores and gaps in the insulating material wound around the coil, which can easily absorb moisture and reduce the insulation resistance. Vacuum drying not only can absorb moisture but also improve the moisture-proof ability of the coil and enhance its electrical insulation strength. Secondly, when stopping vacuum drying, the moisture should be removed first. The purpose of drying is to promote the polymerization and oxidation of the impregnated paint, making the paint impregnated in the roll hard and forming a smooth paint film on its surface. It mainly consists of the following aspects:

Improve the moisture-proof performance of the solenoid valve coil within the group. In the coil winding, whether it is the phase between the slot insulation, heat preservation and heat insulation layers, the connection between the threads, or the power supply wires, there are a large number of capillary pores in the inner layer, which are prone to absorbing moisture from the air and reducing their own insulation performance. After the paint dries, moisture is driven out of the capillary pores, filling the insulating paint and forming a bright surface. Moisture and corrosive gases are less likely to penetrate, thereby enhancing the insulation and corrosion resistance between each turn.