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7. Compare the pressure indicated on the HMI LCD display at the transition (gradual increase to
rapid increase) with the pressure indicated on the system air pressure gauges.
NOTE: The pressure indicated on the HMI LCD display at the transition of gradual to rapid
increase will be the pressure at which the AMD pressure regulation device is currently
set.
a. If the pressure indicated on the HMI LCD display at the transition (gradual increase to rapid
increase) is the sprinkler system’s target pressure, proceed to 9.
b. If the pressure indicated on the sprinkler system’s air pressure gauge at the transition
(gradual increase to rapid increase) is LESS THAN the sprinkler system’s target pressure,
proceed to 8a.
c. If the pressure indicated on the sprinkler system’s air pressure gauge at the transition
(gradual increase to rapid increase) is MORE THAN the sprinkler system’s target pressure,
proceed to 8b.
8. Pressure settings.
a. If the pressure on the sprinkler system’s air pressure gauge is LESS THAN the target
operating pressure, increase the pressure setting of the AMD by ¼ of a turn increment (cw)
(increment can be different at discretion of operator) and return to 5.
b. If the pressure on the sprinkler system’s air pressure gauge is MORE THAN the target
operating pressure, decrease the pressure setting of the AMD by ¼ of a turn increment
(ccw) (increment can be different at discretion of operator) and return to 4.
9. Repeat 5, 6 and 7 to verify that the operating pressure readings are consistent.
a. If the pressure reading is as expected, mark the location of the indicator on the sprinkler
system air pressure gauge of the system being tested (and on the AMD pressure gauge if
applicable).
10. Additional sprinkler systems.
a. Other sprinkler systems not tested: If there is another system supplied by the nitrogen
generator, proceed to that system and return to 2.
b. No other sprinkler systems to test: If there are no other systems supplied by the nitrogen
generator to be tested, proceed to 11.
11. Test operation of nitrogen generator with all sprinkler systems operating.
a. Confirm AMD fast fill (bypass) valve(s) are closed and the regulated valve(s) are open on all
the system AMD(s).
b. Slowly drain 1-2 psi (.07-.14 bar) of pressure out of one (1) of the sprinkler systems.
c. Use the flow meter ball valve to relieve gas from nitrogen/air supply line to sprinkler system
AMDs allowing the nitrogen generator to turn on.
d. Allow nitrogen generator to fill the sprinkler system(s) and turn-off.
e. Compare sprinkler system pressures on all systems are the same as the target operating
pressure.
f. If system pressures are NOT the same as the target operating pressure, repeat 8, as
necessary.
g. If system pressures are the same as the target operating pressure, proceed to 12.
12. Determine the nitrogen generator cut-in (turn-on) pressure by subtracting 5 psig (.3 bar) from the
target system operating pressure determined at the beginning of this procedure.
a. If subtracting 5 psig (.3 bar) from the target operating pressure results in a cut-in (turn-on)
pressure that is within 3 psig (.2 bar) of the low air alarm, subtract 3 psig (.2 bar) from the
target operating pressure.
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