Nortec AIRFOG Series - Manual (Page 36)

32 | AirFog Installation Manual
to random events.
Repair the identified problems and verify the system is fully operational using the procedure
described in the Start Up section of this guide.
Unscheduled Maintenance
Normally an unscheduled maintenance activity is initiated by an observation of a leak or other
failure.
 The AirFog system is to be shutdown in accordance with the procedure described in the Shut
Down section of this guide.
 Execute repair action either by repairing the leak or replacement of the suspected
component.
 Record the date, nature of the problem, the repair action taken, other pertinent details and
sign the failure report.
 Comparison with previous inspection records and failure reports could indicate systematic
problems as compared to random events.
 Verify the system is fully operational using the procedures described in the Start Up section
of this guide.
Vacuum Valve Testing
Setup for test:
 Adjust air feed pressure from the control panel to 70 psig.
 Adjust water feed to vacuum valve to 25 psig.
 Adjust vacuum valve regulator to 7 psig. (This adjustment cannot be made until the system
is turned on and a pilot signal of 15 psig or greater is applied.)
 Adjust vacuum valve thumb wheel to zero force (spring backed off).
While system in operating, visually watch the spray pattern from the nozzles.
If the system is completely sealed (no vacuum leaks in the water line) then once the system is
turned on for the first time all nozzles should start spraying starting with the nozzles closest to
the vacuum valve. The negative pressure created in the water line by the high velocity air
exiting the nozzles will cause the water line to fill with water, the farther the nozzle is from the
vacuum valve the longer it will take for the water to reach that nozzle. Once the system has
gone through the priming stage, it should start spraying within seconds after the system has
been turned on after a shut down. The priming stage should not take any longer than five
minutes. If the system fails to fully prime after five minutes this may indicate a problem.
Checking For Vacuum Leaks
The best way to check for leaks is to, bypass the vacuum valve by connecting the nozzle supply
water line and connecting it directly to the system water supply line. This will pressurize the line
and any leaks should cause dripping allowing location and repair of the leaks.
To test the operation of the vacuum valve: