UHV Gate Valves

Solenoid valve designs have many variations and challenges.

Common components of a solenoid valve:

Solenoid subassembly
Retaining clip (a.k.a. coil clip)
Solenoid coil (with magnetic return path)
Core tube (a.k.a. armature tube, plunger tube, solenoid valve tube, sleeve, guide assembly)
Plugnut (a.k.a. fixed core)
Shading coil (a.k.a. shading ring)
Core spring (a.k.a. counter spring)
Core (a.k.a. plunger, armature)
Core tube–bonnet seal
Bonnet (a.k.a. cover)
Bonnet–diaphram–body seal
Hanger spring
Backup washer
Diaphragm
Bleed hole
Disk
Valve body
Seat

The core or plunger is the magnetic component that moves when the solenoid is energized. The core is coaxial with the solenoid. The core’s movement will make or break the seals that control the movement of the fluid. When the coil is not energized, springs will hold the core in its normal position.

The plugnut is also coaxial.

The core tube contains and guides the core. It also retains the plugnut and may seal the fluid. To optimize the movement of the core, the core tube needs to be nonmagnetic. If the core tube were magnetic, then it would offer a shunt path for the field lines. In some designs, the core tube is an enclosed metal shell produced by deep drawing. Such a design simplifies the sealing problems because the fluid cannot escape from the enclosure, but the design also increases the magnetic path resistance because the magnetic path must traverse the thickness of the core tube twice: once near the plugnut and once near the core. In some other designs, the core tube is not closed but rather an open tube that slips over one end of the plugnut. To retain the plugnut, the tube might be crimped to the plugnut. An O-ring seal between the tube and the plugnut will prevent the fluid from escaping.

The solenoid coil consists of many turns of copper wire that surround the core tube and induce the movement of the core. The coil is often encapsulated in epoxy. The coil also has an iron frame that provides a low magnetic path resistance.