Specifications
0 1000 2000 3000 4000 5000 6000
MAXIMUM TORQUE REQUIRED (FT-LBS)
PC0006
Figure 2-3. Power Positioner Torque Chart
2-4. AIR SUPPLY INSTALLATION. Using Figure
2.3, match the torque load needed to position your
device to the “maximum torque required” axis along
the bottom of the graph. From this point, move
vertically up to the control torque curve. From the
point that intersects control torque curve, move.
horizontally to the left scale labeled “supply air
pressure”. This is the minimum supply air required to
develop the required control torque. The stall torque
curve. represents the maximum amount of torque the
power positioner will produce for given supply air
pressure before stalling out.
a. Air Line Requirements. Installation of air filter
is necessary for proper power positioner
operation. A manual shutoff valve should be
installed in the air supply line before the air
filter, Figure 2-4. The air filter will remove finely
dispersed water or oil droplets, preventing pilot
valve stem from sticking.
If your unit is not equipped with an I/P signal
convater, install a separate signal line as shown in
Figure 2-4 View B. The. power positioner can accept
diffmat ranges of signal air pressures. Refer to your
model number and model number matrix (Table.
l-l) to determine signal air pressure required.
b. Supplv Air and Signal Air Connections. Basic
schematics are. shown in Figure 2-4. The
installation of the. air filter is as follows:
1. Mount bracket for air filter directly on the
back of the stand assembly. If this is unsuit-
able, mount air filter within 15 feet of power
positioner.
NOTE
Prior to connecting supply air line or signal
air line, purge air system until all moisture
and debris are blown out.
2. Purge air supply system and connect air
supply line to the air filter inlet. Run a
second line from the air filter outlet to the
power positioner supply air inlet connection.
Supply air fitting is 3/8 inch NPT.
3. Purge signal air line and connect to signal
air connection on power positioner. Signal
air fitting is l/4 inch NPT.
l&102-208
2-3