Agilent Technologies 7890A Troubleshooting Manual page 86

7
Checking for Leaks
Leak Check Tips
WA R N I N G
WA R N I N G
86
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.
Hydrogen (H ) is flammable and is an explosion hazard when
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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.
Hazardous sample gases may be present.
Gather the following:
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• 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.
Check any potential leak points associated with any
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maintenance recently performed.
Check GC fittings and connections that undergo thermal
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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.
Troubleshooting