Leslie Controls Pilot Controller - Manual (Page 5)

Page 5
Dismantling Superstructure
1. Loosen setscrew (63) and disassemble adjusting pin
(64) from stem (13).
2. Remove diaphragm cover (3), diaphragm spring (81)
and diaphragm spring seat (82), diaphragm (6),
diaphragm disc (7), diaphragm spacer (15) and
diaphragm guide (16). Lift out top spring seat (17) with
stem (13), stem nut (19) and yielding spring (18).
Remove adjusting spring (12), bottom spring seat (20),
thrust bearing (21), adjusting nut (22) and locknut (23).
3. Clean all parts. Replace any worn or damaged part. To
disassemble stem (13) from top spring seat (17) hold
top spring seat rigidly on hex, press down on stem and
remove stem nut from top spring seat.
REASSEMBLING SUPERSTRUCTURE
1. Reassemble locknut (23) (countersunk side downward),
adjusting nut (22), thrust bearing (21), bottom spring
seat (20) and adjusting spring (12) to adjusting sleeve
(14). Replace top spring seat (17) with assembled stem
in yoke (10). Place diaphragm guide (16) in recess of
yoke (10).
2. Place diaphragm spacer (15) on yoke (10) with raised
face downward. Position diaphragm disc (7) on top
spring seat (17). Place diaphragm (6), diaphragm spring
seat (82), diaphragm spring (81) and diaphragm cover
(3) on diaphragm. Replace bolts (8) and nuts (2).
Tighten firmly. Reassemble adjusting pin (64) to stem
(13).
REASSEMBLING PILOT BODY ASSEMBLY TO BASE
1. Slide pilot body assembly upward on base so that
adjusting pin (64) passes smoothly through proportional
band blade spring. Replace pilot body screws (36) and
tighten firmly. Reconnect impulse line to diaphragm
cover. Open air supply line. Adjust pilot as described in
Section IV.
SECTION IV - SETTING OF ADJUSTING PIN
Supply 20-22 psig operating pressure to controller. Turn
adjusting nut to compress adjusting spring to set upper
diaphragm against its top limit stop. If possible, remove fluid
pressure from top of diaphragm, if not, compress spring
sufficiently to overcome fluid pressure and move diaphragm
to stop.
For PDAP Adjustable Proportional Band Type
Adjust sliders ZC\zn” apart as shown in sketch below. Move
proportional band nut upward on adjusting pin thread suffi-
ciently to keep nut from touching blade spring during stem
length adjustment. Loosen adjusting pin set screw and turn
adjusting pin either up or down until pilot air output is 0 psig
then turn adjusting pin downward toward pilot body until pilot
air output increases from 0 to 21 psig. Lock set screw. Turn
proportional band nut down against blade spring until air out-
put pressure decreases from 21 to 18 psig. With pin in stem
hole to keep stem from turning, loosen set screw and turn
adjusting pin upward away from pilot body approximately
1Z\v turns. Lock set screw.
For PRAP Adjustable Proportional Band Type
Adjust slider ZC\zn” apart as shown in sketch below. Move
proportional band nut upward on adjusting pin thread suffi-
ciently to keep nut from touching blade spring during stem
length adjustment. Loosen adjusting pin set screw and turn
adjusting pin either up or down until pilot air output is 21 psig.
Then turn adjusting pin downward toward pilot body until
pilot air output decreases from 21 to 0 psig. Lock set screw.
Turn proportional band nut down against blade spring until air
output pressure increases from 0 to 3 psig. With pin in stem
hole to keep stem from turning, loosen set screw and turn
adjusting pin upward away from pilot body approximately
1Z\v turns. Lock set screw.
SLIDER
PILOT TEST DISTANCE
RANGE PRESSURE BAND (PSIG)
MIN. MAX.
(PSIG) (PSIG) BAND BAND MIN. MAX.
5-70 50 2 3 ⁄
4
" 1 1 ⁄
4
" 2.0 - 4.5 7.0 - 11.0
50-800 80 2 3 ⁄
4
" 1 1 ⁄
4
" 5.5 - 8.5 15.0 - 21.
Figure 9. Min./Max. Proportional Band Table
NOTE: When the above adjustments have been properly
made, the proportional bands noted in Table - Figure 9 will be
obtained when the sliders are set the approximate distances
apart as shown.
Figure 8. Position of sliders for nut/blade spring
adjustment
Nut (65)
Slider (70)
13/16"
Slider 975)
Knob
(76)
Stem (13)
Blade Spring (66)