What are the requirements for the installation height of flammable gas detectors?
The core basis for installation height: gas density
According to national standards such as GB 15322.3-2019 Combustible Gas Detectors Part 3: Portable Combustible Gas Detectors for Industrial and Commercial Use, the installation height of combustible gas detectors should be set based on gas density. There are significant differences in the diffusion and accumulation positions of combustible gases with different densities in space after leakage, which is the core element in determining the installation height.
Installation height specifications under different gas densities
1. Combustible gases with a density lower than that of air
When the density of combustible gas is lower than that of air, the leaked gas will float upwards and gather above the space. At this point, it should be installed 0.5-2m above the release source. For example, the main component of natural gas, methane, has a lower density than air. In the area where gas pipelines are laid, installing detectors in the space above the pipeline can quickly capture leaked methane gas and trigger an alarm before the concentration reaches a dangerous threshold, buying time for emergency response.
2. Combustible gases with a density greater than air
If the density of combustible gas is higher than that of air, it will sink and accumulate near the ground after leakage. In such cases, the detector needs to be installed within a height range of 30-60cm from the ground. Components such as propane and butane in liquefied petroleum gas have a higher density than air. When installed at this height in liquefied gas storage tank areas and gas usage sites, they can accurately monitor gas leaks and provide timely warnings of potential hazards.
Precautions for installation of special gases
1. Hydrogen not only has a lower density than air, but also belongs to highly flammable and explosive gases, which are highly prone to explosions due to static electricity. Therefore, when installing a hydrogen detector, it is necessary to ensure that the equipment has intrinsic safety explosion-proof function, and the installation location should be far away from areas that may generate static electricity, such as avoiding direct contact with chemical fiber pipelines and equipment to reduce the risk of static electricity accumulation.
2. Although carbon monoxide has a density similar to air, it is often produced in practical scenarios due to insufficient combustion. When installing a carbon monoxide detector, it is necessary to avoid areas such as automobile exhaust outlets that are prone to cross interference, in order to prevent false alarms caused by carbon monoxide in the exhaust and ensure that the detection results truly reflect the concentration of carbon monoxide produced by leaks in the environment.
3. In a composite gas environment, when multiple combustible gases are detected in the environment, it is necessary to clarify the detection objects of each sensor and set the alarm value based on the gas with the highest danger. At the same time, based on the density characteristics of different gases, the installation positions of instruments are reasonably distributed to achieve comprehensive monitoring of multiple gases.
