Boiler room gas detection systems

Most gas boiler rooms run without permanent monitoring and a gas leak could stay unnoticed. The gas detection controllers for the boiler room mainly remove these risks by triggering valve actuators. In the presence of ignitable gas detection (liquefied petroleum gas or natural gas), a controller will shut down the gas supply with a safety solenoid valve (tools available inside the taps with suitable fittings) placed upstream and, if possible, outside the technical room.

Bigger gas detection systems for boiler rooms are regulated under specific laws but common sense implies same boiler room safety regulations for smaller boiler rooms. For lighter-than-air gases (such as methane), the gas detector should be above the burner; for heavier-than-air gases (such as butane or propane), the device should be below the burner.

For gas boiler rooms with high ceilings (over 3 meters), an additional gas detector is placed at the highest point of the boiler room (or ideally in the extraction intake flow when there is one) to provide double detection (burner and ceiling), whatever the number of burners (boilers).

All the tools needed to operate boiler rooms equipment comply with the standards and regulations in force. June 23, 1978, decree applies to boiler rooms with a capacity of over 70 kw or 85 kw up to 2000 kw and less than 2MW. Sheet 2910 of August 3, 2018, order determines the new modalities by reducing the classification threshold to 1MW for Environmental Protection Classified Installations. This change makes it mandatory to install fixed gas detection in boiler rooms.

A gas detection controller for boiler heating systems manages every fixed gas detector and features relays for alarm signals and valves actuators:

• Level 1: 10 or 15 % of the LEL (lower explosive limit), visual and audible signal with alarm report for fast on-site intervention
• Level 2: Between 20 and 40 % of the LEL, gas supply shutdown through a manual reset boiler gas valve (human action to reactivate the boiler room)
• Level 3: Only for biggest gas boiler heating systems. Starting at 60% of the LEL, direct action on the main LV board and complete shutdown of any power supply (except the boiler room gas detection controller)

Industrial steam boilers are very popular in food, metal, chemical, and other industries. At a time when we're looking for a better way to reduce our energy bills, this type of heating meets today's challenges by being more ecological and environmentally friendly. Results achievement is possible by monitoring the evolution of consumables such as water and gas. Maintenance and control of equipment are also essential for the smooth operation of this steam boiler.

Connected to a gas detection controller, the gas detector inside a technical room housing several boilers is an essential element for the protection of workers. Equipped with high technology, the tools (fixed gas or portable 4-gas detectors) are necessary for proper operation. It alerts quickly in the event of a leak in gas boiler rooms and thus helps to prevent employees from possible explosions or poisoning. Some are suitable for ATEX areas.

The number of devices depends on the quantity of boilers and their location inside the building is fixed according to the risks of leakage. Preference will go to a detector per boiler, a central high-part detector due to the weight of natural gas lighter than air, and a device above the heating equipment to trap gas. In the lower part, there is ventilation with fresh air introduction. In the upper one, you will find an air evacuation system to offer a continuous sweep of the air even during the shutdown of the burners.

Maintenance of all the tools that make up a gas detector in a boiler room is essential. Staff should be available regularly for manual verification, calibration, and prevention. Periodically monitoring and calibration are significant for explosive meter detectors.

The main - and most efficient - action in case of gas presence is the gas supply shutdown through a manual or automatic reset gas safety valve. The product's power supply passes through the gas detection unit (fail-safe relay), which closes as soon as a lack of voltage is detected with an alarm. This gas cut-off ensures optimum safety.

Gas line accessories offer enhanced protection for solenoid valves. The two essential safety products are block valves, which stop the gas flow at a defined point, and gas pressure switches, which measure the minimum presence of gas or excessive pressure. A solenoid valve is an aluminum or brass fitting that opens or closes a circuit by sending an electric current through a magnetic field. It generally has female / female connections to standardized flanges. This range of tools is varied and affordable.

Pressure gauges are also a good complement. It quantifies the pressure of the liquid or gaseous fluid in a heating system. Regular reading of the level is necessary to detect any problems.

The dead-glass box is an excellent safety accessory, protecting the solenoid valve from corrosion.