Routine Maintenance: General
Maintaining a sampling valve (rotary type)
Released: March 2004 6850 Series II GC User Information page 111 of 256
1. Turn off the oven and valve box heater and allow the valve to cool to room
temperature.
Alternately, load the SERVICE method and wait until the GC becomes
READY.
2. Using a control module or data system, set the valve to the OFF position.
3. Turn off the air supply to the valve actuator, then loosen the connection to
the air supply tubing to relieve the back pressure at the actuator. When the
pressure is released, disconnect the supply tube from the valve box. See
Figure 17.
Figure 17. Rotary sampling valve actuator air supply
Loosen tubing at
connection to
air supply to
depressurize
Actuator
Remove screws
to remove
actuator assembly