STEP 5
When the required level is reached, or if the tank is overflowing,
SLOWLY turn the adjustment screw OUT, counterclockwise, in
¼ to ½ turn increments (See Figure 3). A small amount of water
will discharge from the vent/exhaust line of the Altitude Control,
signaling the port connection changes of both the Altitude Control
and accelerator. The valve will start closing as indicated by the
position indicator stem movement See Figure 4).
The following is dependent upon the installation/application and
may not be required on all valves: When the valve is closed, the
Altitude control screw adjustment may be turned OUT, counter-
clockwise, an additional ¼ to ½ turn. This will lower the shut-off
level slightly below the tank over-flow mark, eliminating any wave
action discharge from the over-flow pipe.
STEP 4
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 2B).
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 2A).
STEP 6
Closing Speed Control Adjustment: The closing speed needle
valve regulates fluid pressure into the main valve cover chamber,
controlling the valve closing speed. If the downstream pressure
fluctuates slightly above the desired setpoint, turn the adjustment
screw OUT, counterclockwise, increasing the rate of closing (See
Figure 2B above).
Setting the Altitude Pilot
4 IOM-ACV-127-8_6127-8 2115
EDP# 1917065
© 2021 Watts
IOM-ACV-127-8_6127-8 2115
EDP# 1917065
© 2021 Watts 5
Counterclockwise to INCREASE
the rate of opening
Clockwise to DECREASE
rate of opening
2A
2B
Figure 2
Flow Control
Counterclockwise to DECREASE
minimum tank level set point.
Figure 3
Model 27 - Altitude Pilot
Figure 4
Position Indicator Stem in Down Position
Indicating Valve Closed
