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Setting the Altitude Pilot
STEP 4
Slowly open the downstream isolation valve.
STEP 5
If the valve remains closed as indicated by the stem position in the
position indicator (See Figure 2) and the tank level is known to be
below the desired level, SLOWLY turn the adjustment screw IN,
clockwise, by ¼ to ½ turn increments (See Figure 3).
This will cause the valve to start opening, filling the tank. Additional
clockwise adjustment may be necessary to raise the level to the
overflow line.
STEP 6
Opening Speed Flow Control Adjustment: The Opening speed
needle valve restricts flow out of the cover of the main valve.
If recovery of pressure is slow upon increased downstream de-
mand, turn the adjustment screw OUT, counterclockwise, increas-
ing the rate of opening (See Figure 4B).
If recovery of downstream pressure is too quick, as indicated in a
rapid increase in pressure, possibly higher than the desired set-
point, turn the adjustment screw IN, clockwise, decreasing the
rate of opening (See Figure 4A).
4
IOM-A-ACV-960-17_660-17 2115
Position Indicator Stem in Down Position
Clockwise to INCREASE
minimum tank level set
point.
Clockwise to DECREASE
rate of opening
4A
EDP# 1917058
Figure 2
Indicating Valve Closed
Figure 3
Model 27 - Altitude Pilot
Counterclockwise to INCREASE
the rate of opening
4B
Figure 4
Flow Control
© 2021 Watts
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