Matters Needing Attention During the Use of Combustible Gas Detectors
Once fixed-point detectors are installed in position, their locations are difficult to adjust. Based on years of practical experience, the following factors need to be taken into account during actual deployment.
① Identify all potential leakage points on the monitored equipment, analyze parameters such as leakage pressure and emission direction, draw a layout drawing for probe positions, and classify leakage risks into three levels: Grade Ⅰ, Grade Ⅱ and Grade Ⅲ according to leakage severity.
② Judge the diffusion direction of combustible gas in the event of a large-scale leakage by referring to on-site airflow and wind direction conditions.
③ Establish a three-dimensional diffusion model of leaked gas based on whether the gas density is higher or lower than air and combined with air circulation patterns, then draft an initial layout plan at the downstream of the gas flow. Finalize the installation scheme after comprehensive evaluation, so that the required quantity and model types of detectors can be calculated.
④ For areas with high risk of massive combustible gas leakage, install one detection point every 10 to 20 meters in compliance with relevant specifications. For unattended small pump houses with intermittent operation, install a detector at the leeward side to guard against potential gas leaks.
⑥ In locations with hydrogen leakage hazards, mount the detector on the horizontal plane above the leakage points.
⑦ For gases with density greater than air, install detectors on the horizontal plane below the leakage points while taking surrounding environmental conditions into full consideration. Special emphasis shall be placed on arranging monitoring points in zones prone to
combustible gas accumulation.
⑧ In open environments where combustible gases diffuse freely with poor ventilation, local gas concentration can easily approach or reach the Lower Explosive Limit (LEL). Such areas are critical monitoring points that cannot be ignored. Analysis of on-site accidents shows that more than half of malfunctions stem from improper installation and calibration. Therefore, it is necessary to specify the precautions for correct installation and calibration to reduce equipment failures.
