Perform a Leak Test

This tests all fitting connections in the gas flow path and part of the analysis valve. Any flow reading other than zero indicates a leak in the gas flow path being tested.

  1. Inlet valves
  2. Reference gas MFC
  3. Cold trap valve heat zone
  4. Analysis valve heat zone
  5. Detector heat zone
  6. Auxiliary port
  7. Valve heat zone
  8. Septum
  9. Loop gas MFC
  10. Carrier gas MFC
  11. Reference gas MFC
  12. Calibration valves
  1. Go to Unit [n] > Enable Manual Control. Ensure a checkmark displays to the left of the menu item. If the analyzer schematic does not display, go to Unit [n] > Show Instrument Schematic.
  2. Prepare for the leak test:
  1. Set all heat zones to ambient temperature.
  2. Set all four MFCs to 50 sccm.
  3. Allow the analyzer to cool to room temperature.
  This test must be performed in the order provided to ensure the analyzer is fully tested. Any flow reading other than zero indicates a leak in the gas flow path being tested.

Preparation Gas Path Leak Test

  1. Right-click the analysis valve and select Analyze.
  2. Right-click the first preparation valve and select Open.
  3. Plug the preparation gas exhaust outlet.
  1. Observe the preparation gas MFC reading as it slowly drops to zero. A flow reading of zero indicates the flow path between the preparation gas MFC and the preparation exhaust does not leak.
  1. To fix a leak that may be indicated on the preparation gas MFC, tighten the fittings in the gas flow path and observe the reading for any decrease that would indicate that the leak has stopped.
  Any leak detected in the remaining steps of this procedure may be fixed by using the same process mentioned in Step 5.
  1. Right-click the preparation gas MFC and select Stop Flow. This will close the helium valve.
  2. Remove the plug from the preparation gas exhaust outlet.

Reference Gas Path Leak Test

 

Valve positions need not be preset for this test. Any flow reading other than zero indicates a leak in the gas flow path being tested.

  1. Right-click the reference valves and select Open.
  2. Plug the reference gas exhaust outlet.
  3. Observe the reference gas MFC reading as it slowly drops to zero.

A flow reading of zero indicates the flow path between the reference gas MFC and the reference gas exhaust does not leak. This tests all fitting connections in the gas flow path and the reference side of the thermal conductivity detector.

  1. Right-click the reference gas MFC and select Stop Flow. This will close the valve.
  2. Remove the plug from the reference gas exhaust outlet plug.

Carrier Gas Path Leak Test

  1. Right-click the cold trap valve and select Bypass.
  2. Right-click the analysis valve and select Prepare.
  3. Right-click the loop valve and select Fill.
  4. Turn the pressure control knob on the helium gas regulator to deliver less than 50 psi (345 kPag).
  5. Right-click the carrier gas inlet valves and select Open.
  6. Plug the analysis gas exhaust outlet.
  7. Right-click on calibration valve B and select Close , then repeat the step for calibration valve C.
  8. Observe the carrier gas MFC reading as it slowly drops to zero. A flow reading of zero indicates the flow path between the carrier gas flow MFC and calibration valve B does not leak.
  1. Right-click calibration valve B and select Open .
  2. Observe the carrier gas MFC reading as it slowly drops to zero or remains at zero from the previous test. A flow reading of zero indicates the flow path between the carrier MFC and the carrier exhaust outlet does not leak. This tests all fitting connections in the gas flow path and part of the analysis valve, part of the bypass valve, the transducer, the septum, part of the inject valve, and the analysis side of the thermal conductivity detector.
  1. Right-click the loop valve and select Inject.
  2. Observe the carrier gas MFC reading as it slowly drops to zero or remains at zero from the previous test. A flow reading of zero indicates the flow path between the carrier gas MFC and the carrier gas exhaust outlet does not leak. This tests all fitting connections in the gas flow path, the remaining parts of the loop valve, and the loop.
  1. Install an empty sample tube on the sample port.
  2. Right-click the analysis valve and select Analyze.
  1. Observe the carrier gas MFC reading as it slowly drops to zero or remains at zero from the previous test. A flow reading of zero indicates the flow path between the carrier gas MFC and the carrier gas exhaust outlet does not leak. This tests all fitting connections in the gas flow path, the sample tube, and the remaining parts of the analysis valve.
  1. Install a cold trap (or a delay path) on the cold trap port.
  2. Right-click the cold trap valve and select Trap.
  3. Observe the carrier gas MFC reading as it slowly drops to zero or remains at zero from the previous test. A flow reading of zero indicates the flow path between the carrier gas MFC and the carrier gas exhaust outlet does not leak. This tests all fitting connections in the gas flow path, the remaining parts of the cold trap valve, and the cold trap.
  1. Right-click the carrier valves and select Close to close the helium valve.
  2. Remove the plug from the analysis exhaust outlet.
  3. Reset the pressure on the helium gas regulator to its original pressure.

Vapor Generator Gas Path Leak Test

  This test is applicable only if the vapor generator option is installed on the analyzer.
  1. Right-click the loop valve and select Inject.
  2. Right-click the vapor valve and select Bypass.
  3. Right-click calibration valve C and select Close
  4. Right-click calibration valve D and select Close
  5. Plug the loop gas exhaust outlet.
  6. Plug the vapor generator gas exhaust outlet.
  7. Right-click the loop gas valves and select Open.
  8. Observe the loop gas MFC reading as it slowly drops to zero.

A flow reading of zero indicates the flow path between the loop gas MFC and calibration valves C and D does not leak. This tests all fitting connections in the small section of the gas flow path to calibration valves C and D.

  1. Right-click calibration valve D and select Open.
  2. Observe the loop gas MFC reading as it slowly drops to zero or remains at zero from the previous test.

A flow reading of zero indicates the flow path between the loop gas MFC and the loop gas exhaust outlet does not leak. This tests all fitting connections in the gas flow path, portions of the vapor generator valve, and the tubing up to the inject valve.

  1. Install an empty flask onto the vapor generator port.
  2. Right-click the vapor valve and select Vapor.
  3. Observe the loop gas MFC reading as it slowly drops to zero or remains at zero from the previous test.

A flow reading of zero indicates the flow path between the loop gas MFC and the loop gas exhaust does not leak. This tests all fitting connections in the gas flow path, the remaining portions of the vapor generator valve, and the relief valve in the vapor generator.

  1. Right-click the loop gas MFC and select Stop Flow to close the gas valve.
  2. Remove all exhaust plugs.

Loop Gas Path Leak Test

  This test is applicable only if the vapor generator option is installed on the analyzer.
  1. Right-click the loop valve and select Inject.
  2. Right-click calibration valve C and select Close .
  3. Right-click calibration valve D and select Close .
  4. Plug the loop gas exhaust outlet.
  5. Right-click the loop gas valves and select Open.
  6. Observe the loop gas MFC reading as it slowly drops to zero.

A flow reading of zero indicates the flow path between the loop gas MFC and calibration valves C and D does not leak. This tests all fitting connections in the small section of the gas flow path to Calibration Valves C and D.

  1. Right-click calibration valve D and select Open
  2. Observe the loop gas MFC reading as it slowly drops to zero or remains at zero from the previous test.

A flow reading of zero indicates the flow path between the loop gas MFC and the loop gas exhaust outlet does not leak.

This tests all fitting connections in the gas flow path, calibration valves C and D, and the tubing to the loop valve.