US Patent 9145975 Solenoid with spring plug

A solenoid valve is provided which includes a valve member, an armature for moving the valve member, an electro-magnetic coil for inducing movement of the armature. A coil spring is provided for engagement with the armature, the coil spring has at least a first end being generally cylindrical and a second end contacting the armature. A plug is provided threadably engaged with the spring first end along an adjustable length of the spring.