Slow Actuation of Solenoid Valve Coils after Potting? Check Armature Clearance & Temperature Rise First, Then Select PUR 1680 Polyurethane Potting Compound

Manufacturer: ELAPLUS Electronic Adhesives Category: Industry Application Date: 22 Oct 2026, 10:54 AM If a solenoid valve exhibits slow pull-in, unstable operation or failure to act normally after coil potting, priority should be given to inspecting moving armature clearance, coil temperature rise, assembly alignment and adhesive overflow into non-potting zones, rather than immediately attributing the fault to insufficient insulation of the potting material. For stationary coils and terminal cavities requiring insulation, moisture resistance and auxiliary fixation, ELAPLUS PUR 1680(D70) A/B two-component polyurethane potting compound may be evaluated. Compatibility with the solenoid assembly must be verified on actual hardware. Coil Potting Solenoid valves are widely used in industrial automation, pneumatic controls, hydraulic systems, fluid control and various electromechanical equipment. The basic principle is that energising the coil generates a magnetic field to drive the movable armature, which actuates the mechanical structure to open, close or switch the valve. In some solenoid designs, the coil assembly is potted to protect windings, connection terminals and other fixed electrical components. A properly designed potting scheme provides insulation, moisture protection and mechanical retention. However, inappropriate potting scope, assembly positioning or thermal design can impair the performance of the electromagnetic actuator. Therefore, material selection for solenoid potting must balance electrical protection and mechanical movement requirements. The full encapsulation approach used for static electronic modules cannot be copied indiscriminately to all solenoid configurations. 1. Why Might Potting Cause Slow Pull-In? Reliable pull-in depends on electromagnetic force generated by the coil overcoming spring force, friction and other applied loads. Coil current, magnetic circuit geometry, armature position and operating temperature all affect final actuation. If potting material encroaches into regions intended for free movement, mechanical resistance increases and prevents the armature from travelling through its designed stroke. For constructions where the coil chamber is fully isolated from the armature,…