Preventive Maintenance

Packed column inlet

4.Fully open the mass flow controller counterclockwise and wait 1 to 2 minutes to ensure equilibrium.

5.Turn off gas to the inlet at its source.

6.Wait 10 minutes while observing carrier source pressure. If it drops less than 7 to 14 kPa (1 to 2 psi), the system (through the inlet column fitting) is considered leak free.

Evidence of leakage requires the inlet system be leak•checked.

Repressurize the system as necessary, and

CUse a suitable leak•detectionfluid to check for leakage fittings. Correct or replace leaking fittings as needed.

Caution

Leak•detectionfluids often leave contaminating residues; after each

 

application, the area checked should be rinsed with CH3OH (methanol)

 

and allowed to dry.

CAfter verifying fittings are leak•free,there are two locations at the inlet itself where leakage may occur: at the septum, and at the column connection.

-The column connection is checked using a leak•detectionfluid.

-The septum is checked with a bubble flow meter by pressing its rubber inlet tube tightly onto the needle entrance in the septum retainer nut or simply replacing the septum.

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