Agilent Technologies 6890N, Troubleshooting Manual

Page: 78 / 102

78 Troubleshooting
7
Checking for Leaks
Leak Check Tips
When checking for leaks, consider the system in two parts:
external leak points and GC leak points.
• External leak points include the gas cylinder (or gas
purifier), regulator and its fittings, supply shutoff valves, and
connections to the GC supply fittings.
• GC leak points include inlets, detectors, column
connections, valve connections, and connections between
flow modules and inlets/detectors.
1
Gather the following:
• Electronic leak detector capable of detecting the gas type
• 7/16-in, 9/16-in, and 1/4-in wrenches for tightening
Swagelok and column fittings.
2 Check any potential leak points associated with any
maintenance recently performed.
3
Check GC fittings and connections that undergo thermal
cycling, since thermal cycling tends to loosen some fitting
types. Use the electronic leak detector to determine if a
fitting is leaking.
• Start by checking any newly made connections first.
• Remember to check connections in the gas supply lines
after changing traps or supply cylinders.
WA R N I N G
Hydrogen (H
2
) is flammable and is an explosion hazard when
mixed with air in an enclosed space (for example, a flow meter).
Purge flowmeters with inert gas as needed. Always measure
gases individually. Always turn off detectors to prevent
flame/bead autoignition.
WA R N I N G
Hazardous sample gases may be present.