Solenoid Valve Construction Terminology

Bleed-Orifice or Bleed Hole - Small orifice or channel, most often located in the diaphragm or piston of pilot-operated valves, to allow the inlet flow to pressurize the top side of the diaphragm or piston.

Bonnet - Screwed plug or bolted cover on the valve body, on which the core tube with inner parts is fitted.

Coil - Electrical part of the valve consisting of a spool wound with insulated copper wire, which creates a magnetic flux when energized.

Core - A soft magnetic stainless steel part of the solenoid, which is moved by magnetic forces (flux generated by coil).

Core Spring - Spring, which returns the core to the original position when the coil is de-energized.

Core Tube - Stainless steel tube, closed at one end, which isolates the media in the value from external solenoid parts.

Disc/Valve Disc - Sealing material on the core or disc-holder, which shuts off the seal orifice.

Disc-Holder - Valve part, actuated by the core, in which a sealing disk is inserted.

Main Orifice - Principle passage between inlet and outlet of the value