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Self Operated Temperature
Controller Type 4
With globe valves
and
plug balancing
 ◘ Applications:
Temperature controllers for heating installations with
control thermostats for set points from -10 to +1500 °C
and valve sizes DN 15 to 100, nominal pressure PN 16
to 40 and temperatures up to 350 °C.
The valve closes when the temperature rises.
The controllers consist of a control valve with plug
balancing and a control thermostat with temperature
sensor, set point adjustment head with excess
temperature safety device, capillary tube and operating
element. They have the following special features:
●
Self-operated T-controller requiring little
maintenance and no auxiliary energy.
● Tight -closing single- seated valves with plug
balancing, suitable for liquids, gases and vapors
especially for the heat exchangers water, oil and
steam.
●
Valve bodies of cast iron, cast carbon steel or stainless steel.
Pressure Temperature Diagram
acc. to DIN
2401
The operating and
differential pressure specified are
determined by the pressure.
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Figure 2: Principle of Operation |
- Control valve
1) Valve body
2) Seat
3) Plug
4) Bellows housing
4.1) Balancing bellows
4.2) Venting screw
5) Plug stem
5.1) Spring
6) Threaded connection
- Thermostat
7) Coupling nut for the valve
attachment
8) Operating element
9) Pin of the operating element
10) Operating metal bellows
11) Capillary tube
12) Key for set-point adjustment
13) Set-point dial
14) Spindle and pin for set-point
adjustment
15) Excess temperature safety
device
16) Coupling nut
17) Double spindle
18) Piston
19) Temperature sensor (bulb sensor)
◘ Principle of operation (Fig.2)
The controller operates acc. to the liquid expansion
principle. The temperature sensor (19) capillary tube
(11) and operating element (8) are filled with an
expansion liquid. The temperature dependent change
in volume of the liquid contained in the bulb sensor
moves the operating metal bellows (10) of the
operating element (8) and the plug stem (5) of the valve
via the pin (9). The set point is indicated on the scale
(13) and can be adjusted by turning the cylinder (12).
Thus the base of the top and bottom guided piston (18)
is moved via the threaded spindle (14). The
corresponding change in volume is transmitted to the
operating bellows (10) and the plug stem (5) of the
valve. The position of the plug stem (5) with the
attached plug (3) and hence the free area between the
valve plug (3) and the seat ring (2) control the rate of
flow.
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