Boiler room gas detection systems

Most of gas boiler rooms run without permanent monitoring and a gas leak could stay unnoticed. Boiler rooms gas detection controllers mainly remove these risks triggering valve actuators. In presence of any flammable gas detection (liquefied petroleum gas or natural gas), a controller will shut down gas supply with a gas solenoid valve installed outside the boiler 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 gases that are lighter than air - such as methane - the detector will be placed above the burner. For gases heavier than air - such as butane or propane - the detector will be placed below the burner.

For optimal boiler room gas detection, an additional detector shall be placed at an upper point in boiler rooms with high ceilings (beyond 3 meters). It can also be placed in the extraction system to have twin detection (burner and ceiling) regardless of the number of burners (furnace).

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)

The gas detector inside a boiler room is an essential element for the safety of workers. The high-tech monitors (central gas detection systems, fixed gas detectors or portable multi-gas detectors) provide a quick warning of leaks in gas-fired boiler rooms. Some are suitable for ATEX zones.

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. As this solenoid valve is controlled by a gas detection controller, it will close through a tension interruption in case of an alarm…