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Setting the Altitude Pilot
STEP 6
Slowly open the downstream isolation valve.
STEP 7
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 8
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
demand, turn the adjustment screw OUT, counterclockwise,
increasing 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
setpoint, turn the adjustment screw IN, clockwise, decreasing the
rate of opening (See Figure 4A).
4
IOM-A-ACV-960-15-17_660-15-17 2115
Position Indicator Stem in UP Position
Clockwise to INCREASE
minimum tank level set
point.
Model 27 - Altitude Pilot
Clockwise to DECREASE
rate of opening
4A
EDP# 1917064
Figure 2
Indicating Valve OPEN
Figure 3
Counterclockwise to INCREASE
the rate of opening
4B
Figure 4
Flow Control
© 2021 Watts
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