Functional description of the Herschel liquid helium valve.

			Position Indicator For detecting the valve 'open' position, the valve provides an external position indicator, comprising: 15 Indicator housing 16   Reed switch 17   Wiring Actuator Assembly Valve flow elements Functional Description Views of the valve Back to the valve index page

Functional description of the Position Indicator.

The Herschel liquid helium valve incorporates an external position indicator to show the 'valve open' position. The position indicator comprises a reed switch 16, which is activated the moment the armature comes into contact with the upper limit stop - causing the valve cap 6, to become magnetised.

The individual switching behaviour of the valve is verified by detecting the current variation versus the switching time of the valve.