Nortec Industries Airfog Series - Manual (Page 47)

10-50
Page 40
2008-04-11
a visual difference 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.
(3) Release the thumb wheel tension and, once again, there should be a noticeable
change in the nozzle output.
C. 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.