Nortec AIRFOG Series - Manual (Page 37)

AirFog Installation Manual | 33
 Reduce the control panel pressure to 40 psig.
 Adjust thumb wheel tension by turning it in a clockwise direction. There should be a visible
decrease in the output of the nozzles as more tension is applied to the spring. Be sure not
to press down on the thumb wheel while turning it.
 Release the thumb wheel tension by turning clockwise, a visible decrease in nozzle output
should be observed.
The spring tension of the vacuum valve restricts the flow of water to the nozzles by changing
the required amount of vacuum needed to operate the vacuum valve. Since the nozzles can
only generate a fixed amount of vacuum (negative pressure) the flow rate of water is
reduced which causes a finer spray and less output. If there was a vacuum leak in the water
line it may not be noticeable with the vacuum valve spring tension set to zero, but it should
become noticeable with greater tension applied to the spring. A good indication of a small
leak would be very little visual difference in nozzle output while performing this test. Other
symptoms of vacuum leaks include visible, bubbles in the water lines leaving the vacuum
valve or entering the nozzles puttering or intermittent nozzle output may also indicate this
problem.