To Perform A Vi Pressure Decay Test - Agilent Technologies 7890 Series Troubleshooting Manual

7
Checking for Leaks

To Perform a VI Pressure Decay Test

To Perform a VI Pressure Decay Test

166
See the procedure below.
For information on running the pressure decay test for the VI,
refer to your GC user documentation.
If the test fails:
• Check the plugged column fitting and septum purge cap.
• Tighten the pneumatic connections to the volatiles interface.
Install new seals as needed.
• Tighten the split vent trap if needed, or
cartridge and O-rings.
• Tighten the split vent trap if needed, or
cartridge and O-rings.
• Use an electronic leak detector to check the tubing from the
interface to the flow module.
• Use an electronic leak detector to check the flow module for
leaks.
The pressure decay test checks for leaks from the inlet flow
module up to the column fitting.
Initially test the VI with a sampling system installed. If the
system fails the leak test, then isolate the VI from the sampler as
described in "To Prepare the VI for a Closed System Leak
Check" on page 170.
After performing maintenance, first check for leaks in
externally accessible areas. See
If a leak is known to exist, check the externally accessible inlet
fittings first, especially any connection that has seen recent
maintenance, such as the column connection, split vent line,
and so forth.
The pressure decay leak test described below requires removing
the column and capping the inlet column fitting. This test
can/cannot find the following types of leaks:
install a new
install a new
"To Check for External
Agilent 7890 Series Troubleshooting
Leaks".