Design And Principle Of Operation - Samson 43-3 Mounting And Operating Instructions

3 Design and principle of
operation
Î See Fig. 3-1
The regulator consists of a Type 2433 Three-
way Valve (designed as mixing or diverting
valve) and a Type 2430 Control Thermostat
with set point adjuster, a capillary tube and
temperature sensor.
A temperature sensor operating according to
the adsorption principle is used as standard.
Note
Details on the Type 2430 Control Thermostat
with a temperature sensor operating accord-
ing to the vapor pressure principle can be
found in the mounting and operating instruc-
tions u EB 2430.
The valve body is made of red brass or
spheroidal graphite iron.
The Type 2430 Control Thermostat is at-
tached to the valve body (1) using the cou-
pling nut (5).
The temperature regulators work according
to the adsorption principle. The temperature
of the medium creates a pressure in the sen-
sor (48) which is proportional to the mea-
sured temperature. This pressure is trans-
ferred through the capillary tube (11) to the
operating element (12) and converted into a
positioning force. This force causes the pin of
the operating element (10) to move the plug
stem (4) with the plug (3). The plug is not
pressure-balanced.
By turning the set point adjuster (8), the
point of response is changed over the plug
EB 2173 EN

Design and principle of operation

spring. As a result, the temperature set point
is changed.
Depending on its plug arrangement, the
three-way valve is either used for mixing or
diverting service.
In mixing valves, the process media to be
mixed enter at valve ports A and B. The
combined flow exits the valve at port AB.
When the temperature rises, port A opens
and port B closes.
In diverting valves, in contrast, the process
medium enters at the valve port AB and the
partial flows exit at ports A and B. When the
temperature rises, port A closes and port B
opens.
Version with safety thermostat
When a Type 2439 or Type 2403 Safety
Thermostat is attached to the valve or the
regulator, this combination functions as a
safety temperature limiter (TR/STL) or a safe-
ty temperature monitor (TR/STM).
Details in mounting and operating instruc-
tions
u EB 2185 (STL); u EB 2083 (STM).
Version with double adapter
The temperature regulator can be equipped
with a double adapter to connect an addi-
tional control thermostat to control a further
control variable.
See Data Sheet u T 2176.
3-1