4
Temperature Pilot Valve Disassembly
See Figure 5-1 on Page 5.
1. Before removal of capillary system make sure the capillary
system temperature is not exceeding the upper limit of the
capillary range see Table 5-1. Otherwise capillary bellows
rupturemayoccur.Removethermalbulbrstandletcool.
2. Loosen lock nut (16) and turn adjusting screw (15)
counterclockwise (left), freeing up adjusting spring (14).
3. Remove four hexagonal bolts (17) from the pilot valve
spring housing (2) and remove the adjusting spring (14),
bottom spring plate (11), and spring plate
follower (12).
4. Remove top bellows plate (6) and top bellows seal (5).
Check for cracks in top bellows seal if you notice that
condensate was present.
Caution: Be sure that the isolation valves at the inlet and outlet side of the regulator are closed and all
internal pressure has been relieved before disassembly of the valve.
Installation of Capillary System and Thermal Bulb
1. After the pilot body has been installed, install the capillary
system. See Figure 5-1 on Page 5. Be sure to insert
bellows follower (10) as shown in Figure 4-1.
2. Thermal bulb (23) may be installed in any position.
However, care should be taken so that at least three
quartersofthethermalbulbistouchingtheheateduidor
airow.
3. Screwinbushing(24)rstandattachthermalbulb(23).
See Figure 5-1 on Page 5.
4. Do not twist or bend capillary tube (26) sharply. Bending
radius of capillary tube (26) should not be more than 1-1/2”
inches. Position capillary tube (26) so that it does not
touch steam lines.
5. Installathermometerintotheuidclosetothethermal
bulb. See Figure 3-1 on Page 3.
6. When using the thermal bulb in a pipe, make sure the
thermalbulbisinstalledinalocationwheretheheateduid
owsfreelyaroundit.
7. If a thermal well is used make sure heat transfer compound
is applied to the thermal bulb to take up any air gaps before
installation into the thermal well.
Regulating Method
1. Close inlet and outlet valves to temperature regulator and
open bypass line (if installed) to clean the system. Be
sure to close the bypass line after cleaning the system.
During blowdown, make sure that the temperature does
not rise higher than the maximum limit of the capillary unit,
otherwise damage to the capillary unit may occur.
2. Turn the adjusting screw (15) and align the gauge needle
with the required temperature position on the dial. See
Figure 4-1 and Table 5-1. Temperature will rise when
turning clockwise (right) and temperature will fall when
handle is turned counterclockwise (left).
3. Slowly open inlet and outlet valves completely.
4. Allow the system to stabilize and readjust according to the
temperature reading on the thermometer.
Maintenance Inspection
1. Troubleshooting Hints - many of the problems that occur
with temperature regulators are due to dirt holding the main
or pilot valve open. Also make sure that the thermometer
sensingtheuidtemperatureisoperatingcorrectly.
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5. Loosen capillary ring/union (22) and temperature sensor
bellows (35). Make sure not to lose bellows follower
(10).
6. Loosen the guide (7) and remove the bottom bellows plate
(8) and the bottom bellows seal (5) from the bottom half of
the temperature pilot.
7. Remove pilot valve (3).
8. For assembly procedure, follow in reverse order.
Disassembly
