a compact , high response regulating valve has a solenoid modulated armature and plunger construction . the solenoid assembly and armature minimize magnetic flux leakage by maintaining the armature in close proximity to the induced magnetic field . in one embodiment , the lightweight armature has a number of holes to increase the speed at which it may be modulated . mounted to the armature is a regulator plunger which controls fluid communication between the valve &# 39 ; s inlet and outlet ports . normally spring - biased closed , the plunger uses a line seal to maximize flow with minimal longitudinal plunger movement . plunger response time is enhanced by eliminating elastomeric friction . a conical seat and bevelled plunger provide an effective line seal .