Locating Leaks - HP 5890 Series II Plus Reference Manual

Chromatographic Troubleshooting

Locating leaks

Extraneous peaks
Air peaks are sometimes seen in a chromatogram when leakage occurs
because the valve rotor does not seal properly. These leaks may not be
detectable by using the soap•bubblemethod. The leak test procedure is
described in the Site Prep and Installation Manual.
If a leak is suspected but cannot be located with soap bubbles, a pressure
check will determine definitely if a leak exists. Extraneous peaks can
occur sometimes due to improper conditioning of the valve or
contamination. If leaks are not apparent, clean or condition the valve.
Obviously other causes, totally unrelated to the valve, may exhibit
similar symptoms. Impure (i.e., containing water) carrier gas can cause
extraneous peaks.
Locating leaks
Leak•checkingthe plumbing involved in a valve configured system must
be done carefully and methodically. Several methods may be used, and
the best choice will depend upon expediency, accessibility, and the
magnitude of the leak. Refer to Setting initial supply pressures and
leak•testingin the Site Prep and Installation Manual for details.
216