Valco W-Series Minivalves - Agilent Technologies 7820A Service Manual

Agilent 7820 GC Service
231
To reduce the fire hazard when sampling
flammable gases or liquids under pressure,
operators should routinely make pressure-leak
tests of the plumbing, fitting and valves. Both
valve positions should be checked. Depending
on the nature and pressure of the sample
stream, periodic pressure leak test and visual
inspection should be made since wear or use
could cause leaks to develop. Leaks may occur
inside the valve box and be concealed from the
operators view.

Valco W-series minivalves

Valves consist of a driver, valve body, rotor, and preload
assembly.
Valve bodies
Body parts are made from Nitronics 60 nickel steel. If required,
the valve may also be produced from Hastelloy C. External
tubing (plumbing) is connected to the valve body ports by
ferrules and fittings provided with the instrument.
The left (CCW, counterclockwise) and right (CW, clockwise)
stops on general purpose valve bodies limit rotor rotation so the
correct flow path results when the index pin is close to or against
either stop of the index lip.