To Replace A Rotary Valve In The Valve Box - Agilent Technologies 8890 Maintaining Manual

17 Maintaining a Valve

To Replace a Rotary Valve in the Valve Box

To Replace a Rotary Valve in the Valve Box

Do not install a liquid sampling valve (LSV) in the valve box if you plan to heat the box above
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75 °C. Heating an LSV over 75 °C can cause a leak and subsequent explosion. LSVs should
be mounted in the side location to avoid potential explosions.
1 Gather the following:
2 Place GC in maintenance mode: Maintenance > Instrument > Perform Maintenance >
The oven, inlet, detector, and valve box may be very hot.
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Sample and/or harmful gases may be present. Refer to your company's standard operating
procedures for purging the chemicals from the sample line.
3 Set all valves to Off.
4 Leave on the GC and valve actuator air.
5 Turn off the carrier gas and sample line flows and relieve any back pressure to the valve.
The valve box insulation is made of refractory ceramic fibers (RCFs). To avoid inhaling RCF
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particles, we recommend these safety procedures:
• Ventilate your work area
• Wear long sleeves, gloves, safety glasses, and a disposable dust/mist respirator
• Dispose of insulation in a sealed plastic bag
• Vacuum any residual particles and discard
• Wash your hands with mild soap and cold water after handling RCFs.
6 Remove the upper valve box. See
7 Note the tubing connections to the existing valve and label if desired.
8 Disconnect the existing valve fittings.
9 Remove the two T-10 Torx screws attaching the valve to the valve box, then remove the
10 Place the new valve in the valve box. The gap in the index ring on top of a 6-port valve
Maintaining Your GC
• Replacement valve, see
• T-10 Torx screwdriver
• 1/4-inch wrench
• Needle-nosed pliers
• Vacuum
Maintenance Mode > Start Maintenance. Wait for the GC to become ready.
Vacuum any RCF insulation particulates from the valve box area.
valve from the valve box.
points toward the back of the GC if installed correctly. This is the On position. Install and
tighten the two screws with a screwdriver.
"Consumables and Parts for Valves"
"To Remove the Upper Valve Box"
on page 266.
on page 274.
271