Leslie Controls Temperature Fixed and Adjustable Proportional band type - Manual (Page 6)

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2. Turn adjusting screw knob (46) to supply sufficient
operating medium pressure to control valve to bring it
into opening position. See Figure 6 for values and
reference notes on the particular control valve in use.
3.
Open inlet stop valve wide. Partially open outlet stop
valve to permit flow of heating or cooling fluid. Start
flow of fluid to be heated through heater.
4. Adjust temperature pilot to supply sufficient operating
pressure to move control valve to wide open position.
5. Observe temperature rise of fluid under control. When
desired temperature is reached, adjust operating
pressure to control valve by turning adjusting screw
knob (46) until valve just closes.
Increasing/Decreasing Temperature Setting - To
increase or decrease temperature setting turn adjusting
screw knob (46) carefully as indicated by direction of
arrow on cover for type pilot shown.
6.
Check controlled temperature after a period of
operation. Readjust adjusting screw knob (46)
carefully if it is necessary to change temperature
setting.
NOTE: Final adjustment are made best when apparatus is
operating under normal load.
7.
After adjustments are completed tighten lockscrew (3)
just enough to provide sufficient drag to prevent
adjusting screw knob (46) from moving due to
vibration.
WIDENING PROPORTIONAL BAND –
RTP, DTP, etc. See Figure 8
When making initial adjustments for temperature setting in
RTP, DTP, etc. types start with the knob fully clockwise
(narrowest band setting). If an unstable condition appears
in the system, indicating need for widening of proportional
band, turn knob (41) slowly in direction of arrow on knob
(41) to widen proportional band until system stabilizes. (1-
1/4 turns produce widest band.)
NOTE: Readjust set point slightly as desired by turning
adjusting screw knob (46) as in Step 2.
To turn system off first close outlet stop valve then inlet
stop valve.
NOTE: With GP Class Control valves relieve operating
pressure from diaphragm before closing inlet stop valve.
To turn system on with temperature set open inlet stop
valve then slowly open outlet stop valve.
MAINTENANCE
(Refer to figures below or appropriate drawings available
on request.)
DISMANTLING
1.
Remove cover screw (12) and cover (6). Take out
fulcrum pin (26), lever (11) and lever spring (7). In D
types remove lever spring screw (8) also.
2.
Take out diaphragm plate screws (3), diaphragm plate
(1) and diaphragm complete (2) (In RTP, DTP, etc.
types take out spring (43) also). Lift out plunger (20)
and rod (22). To remove rod from tube in D types,
body (5) must be disassembled from base (28) first, by
removing screws (27). (This is only necessary when
rod, plunger or tube must be cleaned or replaced.)
3.
Loosen and remove pilot valve plug (24), gasket (25)
and pilot valve spring (37) (in R and D Types)
In RTP, DTP, etc. types proportioning band screw
(39), pilot valve plug (24), “O” ring (40) and knob
(41) are a subassembly. When pilot valve plug is
removed from body the other parts will follow.
Disassemble proportional band screw from plug.
Clean all parts, replace “O” ring if necessary and
reassemble parts.
CLEANING
Clean all parts including body with an approved solvent.
Make sure body ports are clear. Use crocus cloth to
remove encrusted material. Replace any badly worn or
damaged part.
REASSEMBLY
1.
Reassemble pilot valve (23), pilot valve spring (37),
gasket (25) and pilot valve plug (24) to body. In RTP,
DTP types these parts comprise a subassembly (pilot
valve being replaced by the proportional band screw).
Tighten pilot valve plug.
2.
Reassemble rod (22) and plunger (20) in tube with
recessed end over end of rod. Install diaphragm
complete (2) in body recess with disc end toward
nozzle. In RTP, DTP, etc. types make sure that small
valved portion of disc enters orifice of nozzle. In D
types reassemble body to base.