Leslie Controls Pilot Controller - Manual (Page 2)

Page 2
SECTION I - INSTALLATION
Install pilot controller vertically, in an accessible location.
Allow removal space for ease of maintenance.
Pilot controller may be located above or below line con-
trolled.
IMPULSE LINE CONNECTION AND LENGTH
Connect impulse line from top of diaphragm cover to con-
trolled pressure line. Make connection at least 3 feet from the
valve body opening or the end of any expander. Best results
are obtained when the impulse line does not exceed 30 feet.
Avoid connections near turbulent areas such as those creat-
ed by orifices, elbows, sharp bends, or other flow direction
changing components.
PITCH OR SLOPE OF IMPULSE LINE
Steam and liquid impulse lines should slope toward the sens-
ing head. This ensures that the lines stay full of liquid or
condensate. Pre-fill the sensing line before startup.
For noncondensing gases such as air, slope the lines away
from the pilot, so that any liquid contaminants drain back to
the process. Minimum slope is 1" per foot.
Accessary Equipment
Volume booster relays, positioners, reset relays, derivative
units, etc. may be used with Leslie adjustable proportional
band pilot controllers where system characteristics require
their use.
HYDROSTATIC HEAD PRESSURE
When the pilot controller is installed under the line controlled,
the total pressure resulting from hydrostatic head and con-
trolled pressure must not exceed the maximum range of the
pilot controller
SECTION II - OPERATION
The pilot is factory set and requires no adjustments other than
those necessary to obtain the controlled pressure desired and
the width of proportional band required by the system.
1. Close inlet and outlet stop valves around the control
valve.
2. Open air supply line and impulse line stop valves. Set
proportional band adjustment at “Maximum Band.”
For Pressure Reducing Service Only (Refer to
Figures 6 & 7)
3. Turn adjusting nut (22) of pilot controller counter-clock-
wise until control valve is wide open.
4. Open outlet stop valve partially. Fully open inlet stop
valve slowly.
5. Make final adjustment for desired controlled pressure
value. To increase controlled pressure screw adjusting
nut (22) counter-clockwise. To decrease pressure screw
adjusting nut clockwise.
6. Open outlet stop valve fully.
Figure 1. Pilot Controller Piping Details — Pressure Reduction Station
12"
1"
Slope as shown for condensible gas service 1" per
foot minimum.
Slope toward pilot for steam and liquids.
Impulse LIne-Use 1/2" schedule 40 pipe or tubing
with equivalent I.D.
Avoid loops or pockets in impulse line to insure
true pressure signal to pilot diaphragm.
6" Vertical Section (Min.)
Union
Air Lines-Use 1.4" I.D. pipe or tubing.
Use noncorrosive pipe and fittings.
Connect air supply to Pilot Controller
under gauge marked Operating Supply.
Connect outlet from Pilot Controller
under gauge marked Control Valves to
Diaphragm Control Valve.
LESLIE Class AF-2 Pressure Reducing
Valve. Set reducing valve to supply 20-
22 psig air to pilot.
Stop Valve
Gage