Normally-closed solenoid valves

Normally closed solenoid valves for industrial applications are based on a membrane or piston direct action or servo controlled operating principle. They can be installed on three main branches of a line (liquid line, intake line, and hot gas line). In these valves when the coil is de-energised the plunger stops the fluid flow; whereas, the mobile core of the coil that electrically energises the plunger opens the valve seat connecting the inlet to the outlet. All normally closed solenoid valves are distributed in versions without the coil (S suffix) and in versions with the coil (type HF2).