Leslie Controls DOT 3-WAY CONTROL VALVE - Manual (Page 5)

5
MAINTENANCE OF
VALVE BODY SUB-
ASSEMBLIES
1. DISMANTLING THE DOT 3-WAY
CONTROL VALVE
a. Loosen stem nut. Unscrew the valve plug stem
from the actuator stem. (In large valves, support
the valve plug stem to prevent the valve plug
from suddenly falling downward when the stem
clears. Loosen and remove the yoke capscrews.
Lift the actuator from the bonnet.)
b. Lift the valve stem carefully and pull upwards
until the bonnet and cage come out of the main
body. Remove both “O” rings and lift the load
ring out of the main body. Remove main valve
from cage.
c. Loosen the two set screws and remove the bonnet
from the cage.
d. Remove the packing screws from the packing
flange. Remove the packing follower, packing,
packing washer and packing spring.
2. CLEANING-REPLACING PARTS
Clean all parts thoroughly, including the packing box. Use
an approved, non-residue forming solvent. To remove
encrusted materials use crocus or a very mild aluminum
oxide cloth. Examine all parts. Replace any badly worn or
damaged part.
ACTUATOR
MAINTENANCE
REPLACING
DIAPHRAGMS, ETC.
GENERAL – FOR DIRECT AND REVERSE
ACTING ACTUATORS
Remove Compression on actuator spring by screwing
spring adjustor counterclockwise until actuator spring is
free.
NOTE: Count the number of turns to relax spring
compression. Return to the same setting when assembling.
Figure 3 – Double Ported Control Valve (Single Disc Design)