T 2183 EN
Safety Temperature Monitors (STM) with Type 2403 Safety Thermostat
Series 43 Self-operated Temperature Regulators

Application
Safety temperature monitoring of the energy supply to heat generators and heat exchangers byclosing the valve
For temperature limits from 60 to 120 °C · With valves G ½ to 1 or DN 15 to 50 · Pressure rating
PN 16 or 25 · Max. 200 °C

Safety temperature monitors (STM), with a valve andType 2403 Safety Thermostat, operate without auxiliary
energy and are designed for extended safety according toDIN EN 14597. The safety temperature monitor is used tolimit the temperature by closing a SAMSON Series 43 Valveconnected to the safety thermostat.
Versions
Type 2403 Safety Thermostat consisting of temperature sensor,
limit adjustment knob, capillary tube and operating element.
Safety temperature monitors (STM) (Fig. 1 to Fig. 3)–

Type 2431/2403 · With Type 2431 Globe Valve for G ½
to 1 · PN 25 · Type 2403 STM · 150 °C–

Type 2433/2403 · With Type 2433 Three-way Valve forG ½ to 1 or DN 15 to 50 · PN 25 · Type 2403 STM ·150 °C–15STMSTM

Fig. 1: Type 2431/2403

Fig. 2: Type 2437/2403

1255STM

Type 2432/2403 · With Type 2432 Globe Valve for
DN 15 to 50 · PN 25 · Type 2403 STM · 150 °C–Type 2437/2403 · With Type 2437 Globe Valve for
DN 15 to 50 · PN 25 · Type 2403 STM · 200 °C
Type 2436/2403 · With Type 2436 Globe Valve for G ½
to 1 · PN 16 or DN 15 to 50 · PN 25 · Type 2403 STM;
valve opens in the event of emergency · 150 °C

Fig. 4: TR/STM ·Type 2431/2430/2403
Type 2435/2430/2403

225533u T 2171 – Type 2431 and Type 2432 Globe Valvesu T 2173 – Type 2433 Three-way Valve

STMTRDetails and technical data of the valves are listed in the following data sheets:u T 2172 – Type 2435, Type 2436 and Type 2437 GlobeValves

3Fig. 3: Type 2433/2403

Type 2435/2403 · With Type 2435 Globe Valve for G ½
to 1 · PN 25 · Type 2403 STM · 200 °C––15TR

TR
STM

STM

Fig. 6: TR/STM ·Type 2433/2430/2403

Fig. 5: TR/STM ·Type 2437/2430/2403
1 Type 243X Globe Valve

3 Type 2430 Control Thermostat

2 Type 2433 Three-way Valve

5 Type 2403 Safety Thermostat

SAMSON AKTIENGESELLSCHAFT · Weismüllerstraße 3 · 60314 Frankfurt am Main, Germany
Phone: +49 69 4009-0 · Fax: +49 69 4009-1507 · samson@samson.de · www.samson.de

Edition February 2021

Temperature regulators and safety temperature monitors(TR/STM) (Fig. 4 to Fig. 6) consisting of one of the above listed Type 243X/2403 devices and a Type 2430 Control Thermostat tested according to DIN EN 14597, for example:–the capillary tube (8) to the operating bellows (10) and converted into a positioning force. The force is transferred overthe pin (11) of the operating element to the plug stem (4) andplug (3). The position of the plug determines the flow rate of
the heat transfer medium across the area released between
the seat (2) and plug.

Type 2431/2430/2403 · With Type 2431 Valve · G ½ to
1 · PN 25 · Type 2430 Control Thermostat and Type 2403
Safety Thermostat

The safety thermostat closes the mounted valve when the temperature reaches the adjusted temperature limit. The safety
thermostat resets itself automatically when the temperature has
fallen to a value of approx. 5 K below the adjusted limit.

Further versions– Reduced KVS coefficient in DN 15 or G ½– Safety temperature monitor with differential pressure/flowrate regulation

The adjusted temperature limit must have a minimum temperature difference of 15 K to the set point of the temperature regulator.

Typetesting
The safety temperature monitor is tested by the German Technical Inspectorate (TÜV) according to DIN EN 14597 under
the type designation 2750-5 and available for plants according to DIN 4747-1, DIN EN 12828 and DIN 4753. The registration number is available on request.

Principle of operation (TR/STM)
The connection of an additional Type 2430 Control Thermostat converts the safety temperature monitor (STM) into a temperature regulator with safety temperature monitor (TR/STM).
When the capillary tube ruptures or there is a leak in the sensor, the spring mechanism reacts to the reduced system pressure and the pin of the operating element (11) closes thevalve. The valve cannot be reset. In this case, the Type 2403
Safety Temperature Monitor must be replaced.

Principle of operation (STM)
The safety temperature monitor mainly consists of a valve andsafety thermostat with capillary tube (8) and bulb sensor (9).
See Fig. 7.

Application

The safety temperature monitors work according to the vapor
pressure principle. The temperature of the medium creates apressure in the temperature sensor (9) which is proportional tothe measured temperature. This pressure is transferred throughFurther details on the application of safety thermostats can befound in Information Sheet u T 2181.

12394561186141061312

1Valve body2

Seat3

Plug4

Plug stem

5Valve spring

6

Coupling nut

8Capillary tube

9Temperature sensor

10 Operating element
11 Pin of operating element
12 Limit adjustment knob
13 Lead-seal hole
14

Mounting location for Type 2430
Control ThermostatFig. 7: Combination consisting of Type 2403 Safety Temperature Monitor (STM), Type 2430 Temperature Regulator and Type 2432 Valve

2T 2183 EN

Installation––Valve:

The mounting position of the temperature sensor depends
on the sensor version:

Install the valves in horizontal pipelines. The operating element must be suspended to hang downward.
For Types 2431, 2432 and 2433, other mounting positions are possible for temperatures up to 110 °C.
For Type 2436, the operating element must point upward
for temperatures up to 110 °C.
–Temperature sensor:–Sensor horizontal or tip of sensor pointing up–Sensor horizontal or tip of sensor pointing down

For details on installation u EB 2183.

Capillary tube:
Carefully run the capillary tube (8) without bending or
twisting it. The smallest permissible bending radius is
50 mm.
Observe the permissible ambient temperatures.

Table 1: Technical data · All pressures in bar (gauge)
ValveType2431

2433

24352436 1)½ to 1 · Female thread2432 1)

Connection size

G

Valve size

DN–

15 to 50––

32 to 50–

Pressure rating

PN

2525251625

Max. perm.
temperature°C

150

150200Max. perm. differential
pressurep20

4.4 2)

16–
15 to 25

150162437 1)

820–
32 to 50

15 to 25

32 to 50

2525150200
12168

KVS coefficients forConnection size

G½¾1–

–

–

Valve size

DN

152025324050

KVS with Type 2433

46.3

81012.5

16KVS with Type 2435, 2436,2437

3.24510

12.5

165.7

7.2

1012.516Special versions
KVS with Type 2431, 2432
Special versions–0.4; 1.0; 2.5 3)
3.60.4; 1.0; 2.5–

Type 2403 Safety Thermostat for STM
Limit range

60 to 75 °C or 75 to 100 °C

Perm. ambient temperature

Max. 50 °C

Perm. temperature at sensor

25 K above the adjusted limit

Perm. pressure at sensor

25 barCapillary tube length

5mConformity
Type 2430 Control Thermostat for TR/STM
Set point range

Continuously adjustable: 0 to 35 °C, 25 to 70 °C, 40 to 100 °C, 50 to 120 °C or 70 to 150 °C

Perm. ambient temperature

0 to 50 °C

Perm. temperature at sensor

25 K above the adjusted set point

Perm. pressure at sensor

25 barCapillary tube length

2 m (5 m as special version)

Conformity
1)
2)
3)

DN 15 to 50 also as flanged body valve made of spheroidal graphite iron (EN-GJS-400-18-LT)
For values of other valve sizes, refer to Data Sheet u T 2173
For Type 2436 only

T 2183 EN3

Table 2: Materials · Material numbers according to DIN ENValve

Type2431

2432 1)2435

2436 1)2437 1)

2433

Body

CC491K/CC499K

Seat

Stainless steel 1.4571

Integrated inthe body

Stainless steel with brass 4) and EPDM soft seal 3)

CW617N 4)
with EPDM softseal

Valve plug
Valve spring2)(red brass Rg 5)

Stainless steel 1.4310

Balancing bellows––

Stainless steel 1.4571–

Type 2403 Safety Thermostat for STM with Type 2430 Control Thermostat for TR
Connecting element(Type 2403)

PPO with brass connection nut

Adjustment knob for limit/set
point adjustment

PTFE, glass fiber reinforcedSensor

1.4571

Capillary tubeCopper

DN 15 to 50 also as flanged body valve made of EN-GJS-400-18-LT
Type 2436/G ½ to 1: CW604N (brass)Special version for mineral oils (ASTM I, II, III): FKM soft seal
All brass resistant to dezincification

1)
2)
3)
4)

Table 3: Dimensions in mm
Table 3.1: Type 2431/2403 · Type 2433/2403 · Type 2435/2403 · Type 2436/2403
Connection size

G

½

¾

1

Overall length

L

65

75

90

Type 2431/2403

H140

H

140

Type 2433/2403
Type 2435/2403
Type 2436/2403

H140H

220

H1145

H46

Table 3.2: Type 2432/2403 · Type 2433/2403 · Type 2436/2403 · Type 2437/2403
Valve size

DN

1520253240

50

Pipe Ødd21.3

26.8

32.7

42

48

60

30

36

46

59

65

82

AFLength

L

65

70

75

100

110

130

With welding ends

L1210

234

244

268

294

330

With threaded ends

L2

129

144

159

180

196

228

With flanges

L3

130

150

160

180

200

230

Male thread

A

G½

G¾

G1

G 1¼G 1½G2Type 2432/2403

Type 2433/2403

Type 2436/2403
Type 2437/2403

4H

140

190

H13055

H

135

145

H2112

122

124

144

157

165

H372

77

82

100

108

114

H472

80

82

105

110

115

H–

160

H1–95H

220

270

H13055

T 2183 EN

Safety temperature monitors (STM)
L1
L

H4H1L
L3

G½170255

Ø12Type 2431/2403

Type 2433/2403

Type 2433/2403

Type 2435/2403

Version with female thread

Version with flanges

L1L

L2L

A

SW

H

H

SW

H

SW

H350

H2LdH1d

L1
L

H

H1H

SW

225

30Hd

LH

L

SW

Type 2432/2403

Type 2433/2403

Type 2436/2403

Type 2433/2403

Type 2436/2403

Version with welding ends

G ½ to 1

Version with threaded ends

Temperature regulator with safety temperature monitor (TR/STM)
255
M32 x 1.5

90SW 36125M32 x 1.5170
SW 22SW 17250

G½Ø12Type 243X/2430/2403

T 2183 EN5

Table 4: Weights in kg
Table 4.1: Type 2431/2403 · Type 2433/2403 · Type 2435/2403 · Type 2436/2403½¾1Type 2431/2403

Connection size

G

2.0

2.1

2.2

Type 2433/2403

2.2

2.3

2.4

Type 2435/2403

2.5

2.6

2.7

Type 2436/2403

2.4

2.5

2.6

Table 4.2: Type 2432/2403 · Type 2433/2403 · Type 2436/2403 · Type 2437/2403
Valve size
Type 2432/2403

Type 2433/2403

DN15202550

With welding ends

2.5

2.83.15.1

5.8

7.6

2.4

2.7

3.0

5.0

5.7

7.5

With flanges

3.9

4.8

5.6

8.3

9.8

11.6

With welding ends

2.9

3.2

3.4

4.8

5.1

6.4

With threaded ends

2.9

3.2

3.4

4.8

5.1

6.4

With flanges

5.0

6.2

7.1

9.6

1114

With threaded ends

–With flanges
Type 2437/2403

40

With threaded ends

With welding ends
Type 2436/2403

32

3.8

4.2

4.6

3.8

4.2

4.6

7.0

8.2

9.6

With welding ends

2.7

3.0

3.3

5.5

6.2

8.1

With threaded ends

2.6

2.9

3.2

5.56.2

8.1

With flanges

4.1

5.0

5.8

8.5

1012

Ordering text
Type 243X/2403 Safety Temperature Monitor–

With Type 243X Valve, G … or DN … with welding ends,
threaded ends or flanges (only with Type 2432,Type 2433, Type 2436 and Type 2437)–

For mixing or diverting service · Only with Type 2433–

PN ...

With Type 2403 Safety Thermostat–

Limit range … °C–

Version:–Sensor horizontal or tip of sensor pointing up–

Sensor horizontal or tip of sensor pointing downWith Type 2430 Control Thermostat
Optionally, special version

Specifications subject to change without notice

T 2183 EN

2021-03-18 · English

Optionally, accessories ...