What requirements must be followed when installing toxic gas detectors in tank farm areas?
1, Installation location:
Determine the installation height based on the density of toxic gases. When detecting toxic gases heavier than air, the installation height of the toxic gas detector should be 0.3m~0.6m from the floor (or floor); When detecting toxic gases that are lighter than air, the installation height of the toxic gas detector should be within 2.0m above the release source.
When detecting toxic gases slightly heavier than air, the installation height of the toxic gas detector should be 0.5m-1.0m below the release source; When detecting toxic gases that are slightly lighter than air, the installation height of the toxic gas detector should be 0.5m-1.0m higher than the release source.
2, Horizontal distance:
In storage and transportation facilities, the horizontal distance between toxic gas detectors and any release source within their coverage area should not be greater than 4m.
3, Installation environment:
The toxic gas detector should be installed in a location that is free from impact, vibration, strong electromagnetic field interference, and easy to maintain. The clearance between the detector installation location and surrounding process pipelines or equipment should not be less than 0.5m. It is necessary to avoid high temperature, high humidity, high corrosiveness environments, as well as sources of strong wind and dust pollution.
4, Installation method:
Fixed toxic gas detectors can be installed on rooftops, walls, or pipes, ensuring a firm and reliable installation while considering ease of maintenance and calibration.
5, Wiring requirements:
Wiring should use three core shielded cables, with a nominal cross-sectional area of a single wire greater than 1 square millimeter, and the shielding layer must be grounded during wiring. On site wiring should be carried out through pipes that meet fire safety requirements. The pipes should be connected to probes to meet fire safety requirements.
6, Explosion proof and protection:
When the toxic gas detector is used in explosive environments, it should have explosion-proof performance in accordance with the provisions of GB/T3836.1, GB/T3836.2 or GB/T3836.4, and obtain explosion-proof inspection qualification.
7, Alarm settings:
The first level alarm set value for toxic gases is less than or equal to 100% OEL, and the second level alarm set value is less than or equal to 200% OEL. When the measurement range of existing toxic gas detectors cannot meet the measurement requirements, the first level alarm setting value of toxic gases shall not exceed 5% IDLH, and the second level alarm setting value shall not exceed 10% IDLH.
8, Regular maintenance and calibration:
Regularly maintain and calibrate toxic gas detectors to ensure their proper functioning.
