Combustible gas detection
The same as the electrical fire monitoring system, the combustible gas detection and alarm system is an independent subsystem of the automatic fire alarm system, which is a fire early warning system.
According to the requirements of fire codes, combustible gas alarm devices should be set up in places where combustible gases and vapors may be given off in the building.
Combustible gas detectors shall be installed in places where combustible gases or vapors are used or produced.
Combustible gas detectors should be installed in the following places:
A place where combustible gases are used.
Gas station and gas meter room and storage of liquefied petroleum gas tanks.
Other places emitting combustible gases and vapors.
Combustible gas detector should be set near the location where combustible gas may be generated.
For detecting gas with a density less than that of air, the combustible gas detector shall be located on top of the protected space.
If the density of the detected gas is greater than that of the air, the combustible gas detector shall be located in the lower part of the protected space.
When the density of the detecting gas is comparable to that of the air, the combustible gas detector may be located in the middle or on top of the protected space.
According to the provisions of the urban gas design code, the setting of the gas concentration detection alarm should meet the following requirements:
When detecting gas lighter than air, the horizontal distance between the detection alarm and the fuel or valve shall not be greater than 8 meters, the installation height shall be less than 0.3 meters from the ceiling, and shall not be located above the fuel.
When detecting gas heavier than air, the horizontal distance between the detection alarm and the fuel or valve shall not be greater than 4 meters, and the installation height shall be less than 0.3 meters from the ground.
For petrochemical and other places, the protection radius of the point type combustible gas detector should comply with the national standards and the relevant provisions of the petrochemical combustible gas and toxic gas detection and alarm design code.
The alarm signal of combustible gas detector involved in process control in petrochemical industry should be connected to the fire control room.
The combustible gas detection and alarm system should meet the explosion protection requirements when it is installed in the place with explosion protection requirements.