Sensor for Detection of the Opening or Leaking of the Safety Valves

Technical data: STG-B & STG-F-LEAKDETECTOR

The STG sensor has the function of detecting any leakage or opening of the safety valves in industrial refrigeration systems, operating with any type of refrigerant gas.

When the warning or alarm value of the presence of refrigerant gas is exceeded (Threshold values ​​set by the user), the device will signal the alarm to the controller and activate a visual signal locally. Furthermore, through the MODBUS protocol it is possible to view values ​​such as% Gas Presence,% Alert Gas Presence and Alarm Gas Presence% and set the relative thresholds.

Available in 2 different versions:
STG-B-LEAKDETECTOR: Equipped with a relay with three contacts (C-NO), a Modbus RS-485 protocol and powered by 24 V DC.

STG-F-LEAKDETECTOR: Equipped with a relay with three contacts (C-NO), a Modbus RS-485 protocol, two analogue outputs 0-10V and 4-20 mA and powered in 24 V DC.

In addition, both versions will be equipped with a local visual alarm signal that also allows the display of the status in real time.
By means of the 1 ”threaded connection with which it is equipped, the STG sensor can be easily installed on a pipe leaving one or more safety valves present in the system. It can be used in stand-alone applications or connected through the analogue, digital outputs, or through the RS485 Modbus serial link, to a control system (electronic controllers, PLC or third-party devices) capable of carrying out any alarm procedures.

Delivered without a cable but with a plug. Find the specifications for the plug under the tab Specifications.

This device offers the possibility to intervene promptly in the event of opening or leakage of one or more safety valves, in order to avoid the dispersion of refrigerant gas into the environment, any downtime and to contribute to the guarantee of greater safety for the people who work. nearby.

Product features

It signals the escape of refrigerant gas, avoiding its dispersion in large quantities
Suitable for any type of refrigerant
Compatible with any brand and model of safety valve
Retrofit on any type of system
It can be interfaced with the most common plant control systems
Visual alarm signaling
Easily installable
Long duty cycle
Reusable even after your surgery
It reduces intervention and maintenance costs in case of opening one or more safety valves
Increases safety for people operating nearby
It does not generate pressure drops


Stg application


Power supply
Voltage24 V DC ± 25% (100 mA)
Plug connectionM12 female connector to cable
Plug specificationsM12, A-Coded, 8-pin, female, straight
Contact functionNO
Environmental conditions
Ambient / operating temperature-20...+50°C
Protection degreeIP65
Mechanical specifications
Process connection: 1 ”GF Swivel
Certification: ATEX II 3G Ex ic mc IIA T4 Gc

Ordering code

OutputOrdering code
Relay C-NO (30V - 1A); Modbus RS-485; 4-20 mA (STG-F only); 0-10V (STG-F only)STG-F-LEAKDETECTOR
Relay C-NO (30V - 1A); Modbus RS-485STG-B-LEAKDETECTOR