Medical Gas Outlet Analyzer 'FLOW VALVE PROBLEM'

The flow valve on the Medical Gas Outlet Analyzer is designed to open and close freely under normal operating conditions.  However there are times when the valve can become restricted due to contaminates which have built up in the Plexiglas manifold.  These restrictions can often cause the analyzer to display the message 'FLOW VALVE PROBLEM' and automatically shut down.  The earlier model of the Gas Analyzer flow valve shown in Figure 1, will experience this problem more often than the latest version shown in Figure 2.  To help avoid this problem it is very IMPORTANT to purge the outlets before testing with the analyzer and to keep the chambers in the Plexiglas manifold clean at all times.  To clean the Plexiglas manifold follow the cleaning instruction in the Gas Analyzer manual.  If your manual does not have the cleaning instructions please contact NST.

Figure 1.                                                             Figure 2.        

If your analyzer is experiencing problems with the flow valve sticking or remaining open, the following procedure will explain the steps necessary to free or close the valve.

1. Attach the Battery Charger to the Gas Analyzer and press the right arrow button on the front  panel to turn the analyzer 'ON'.

2. With the analyzer displaying the message 'CHARGING BATTERIES', press and release the up and down arrow buttons on the front panel simultaneously.  The analyzer display should change  from 'CHARGING BATTERIES' to 'PROBE: NONE'.  The analyzer is now in the manual test mode.

3. While watching the flow valve, press and hold the right arrow button on the front panel.  This  will free the restricted flow valve and continue to open the flow valve until the button is released.

4. Once the flow valve has been freed, release the right arrow button.

5. While watching the flow valve, press and hold the left arrow button on the front panel.  This will close the flow valve until it is resting against the brass manifold connector on the rear of the Plexiglas manifold.  Once the valve is closed, release the left arrow button.

6. Repeat steps 3, 4 & 5 two or three times to ensure that the valve is free.

7. Press and release the up and down arrow buttons on the front panel simultaneously to exit  the manual test mode.

This procedure should free the valve, allowing more testing to be completed.  Purging the outlets prior to testing and keeping the Plexiglas manifold clean will help reduce the frequency of the 'FLOW VALVE PROBLEM'.  If you continue to have these problems contact NST at 800.678.7074 to arrange having your analyzer returned for evaluation.