To Replace A Gas Sampling Valve Loop - Agilent Technologies Agilent 7890 Series Maintenance Manual

19
Maintaining a Valve

To Replace a Gas Sampling Valve Loop

WA R N I N G
WA R N I N G
338
1 Gather the following:
• Replacement sample loop. (See
for Valves" on page 336.)
• 1/4- inch wrench
• Vacuum cleaner
Load the GC maintenance method
2
become ready.
3 Turn off the detector.
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
5 Leave on the GC and valve actuator air.
6 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 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.
7 Remove the upper valve box. (See
Valve Box" on page 344.)
Vacuum any loose particulate insulation.
8
When the valve is cool, loosen the sample loop's two
9
1/4- inch 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