Agilent Technologies 6890 Series Service Manual page 632

1110 Valves
Introduction
Specific part numbers are not given in this portion of the service manual. For
all replacement part numbers, refer to the IPB portion of this document.
This document does not provide instruction for first time installation of any
of the options discussed. The add-on sheets, which accompany the various
options, exist for just this purpose, and should be referenced when performing
a first time installation.
The valves described in this manual are W-series minivalves, manufactured
by VALCO Instruments Co, Houston, Texas. The valve body is made of
Nitronic-60 nickel steel with 1/16-inch fittings.
Proper instrument operation will prolong the life of the valve system. Read
all the accompanying information and avoid the following operational abuses:
• Exceeding the specified temperature and pressure ranges
• Plugging a valve with column packing or sample precipitation
• Scoring valve surfaces with column packing or particulates in liquid or
gas sample
• Contaminating the system with samples (non-eluting materials) or poor
quality support gases
Because valves operate best at a constant temperature, the 6890 GC places
valves in their own heated compartment.
WARNING 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.
Jun 2001
Valves
Agilent 6890 Gas Chromatograph Service Manual
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