Agilent Technologies Agilent 7890 Series Maintenance Manual page 159

Guide cap
PTFE ferrule
Ferrule, 1/16-inch
PTFE
Carrier gas tube
C A U T I O N
Maintaining Your GC
Unscrew the guide cap from the head and remove the
6
PTFE ferrule.
7 Carefully insert a syringe with a 23- gauge needle into the
head to press the valve body and Kalrez seal slightly out
of the head.
8 Gently tap the head on a soft, smooth surface so that the
valve body falls out completely or slips out far enough to
grasp with fingers.
9 Remove the Kalrez seal from the valve body.
10 Clean all components in hexane.
Wear clean, lint-free gloves to prevent contamination of parts with
dirt and skin oils.
11 Replace the PTFE ferrule. (See
Septumless Head PTFE Ferrule on the PTV Inlet"
page 161.)
12 Wearing clean lint- free gloves, reassemble the head in
reverse order. Be sure that the seals and the pressure
spring are not damaged.
13 Finger- tighten the septumless head, then tighten an
additional 1/8 turn with a wrench.
Reconnect the carrier gas line.
14
Check for leaks; if necessary, slightly tighten the guide
15
cap with the syringe needle inserted.
• If the head leaks with the syringe inserted, replace the
PTFE ferrule.
Maintaining the PTV Inlet
Kalrez seal
Valve body
Pressure spring
Viton seal
Sealing element
"To Replace the
9
on
159