To Replace A Gas Sampling Valve Loop - Agilent Technologies 7820A Manual

15
Maintaining a Valve

To Replace a Gas Sampling Valve Loop

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276
Gather the following:
1
• Replacement sample loop. (See
for Valves" on page 274.)
• 1/4-inch wrench
• Vacuum cleaner
Load the GC maintenance method
2
become ready.
Turn off the detector.
3
The oven, inlet, detector, and valve box may be very hot.
Sample and/or harmful gases may be present. Refer to your
company's standard operating procedures for purging the
chemicals from the sample line.
Set all valve box 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
6
back pressure to the valve.
The valve box insulation is made of refractory ceramic fibers
(RCFs). To avoid inhaling RCF particles, we recommend these
safety procedures:
1. Ventilate your work area
2. Wear long sleeves, gloves, safety glasses, and a disposable
dust/mist respirator
3. Dispose of insulation in a sealed plastic bag
4. Vacuum any residual particles and discard
5. Wash your hands with mild soap and cold water after handling
RCFs.
Remove the upper valve box. (See
7
Valve Box" on page 282.)
Vacuum any loose particulate insulation.
8
When the valve is cool, loosen the sample loop's two 1/4-inch
9
fittings on the valve head and remove the loop.
"Consumables and Parts
and wait for the GC to
"To Remove the Upper
Maintaining Your GC