User guide

Checking for Leaks 6
Advanced User Guide 133
To Perform a PP Inlet Pressure Decay Test
The pressure decay test checks for leaks from the inlet flow
module up to the column fitting.
After performing maintenance, first check for leaks in
externally accessible areas. See “To Check for External Leaks”.
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 septum nut, column adapter, column
connection, 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:
1 Gather the following (see Consumables and parts for the
purged packed inlet):
• No- hole ferrule
• 1/4- inch wrench
• 7/16- inch wrench
• Heat- resistant gloves (if the inlet is hot)
• 9/16- inch wrench
• 1/8- and 1/4- inch Swagelok caps
• ECD/TCD Detector plug (part no. 5060- 9055)
2 Load the inlet maintenance method and wait for the GC to
become ready.
3 Remove the column, if installed.
The test can find leaks at the: The test cannot find leaks at the:
septum column fitting
septum nut gas supply bulkhead fittings to the
flow module
glass insert O-ring seal
adapter and ferrule
inlet body
top insert weldment
seals within the tubing between the
inlet flow module and the inlet body