Precautions for Using Portable Combustible Gas Detectors
① For locations with potential hydrogen leakage, the detector shall be installed on the plane above the leakage point.
② If a site carries high risks of large combustible gas leakage, one detection point shall be arranged every 10–20 meters in accordance with relevant regulations. For small pump houses operating intermittently, attention shall be paid to possible combustible gas leakage, and one detector shall generally be installed at the leeward side.
③ In open environments where combustible gas diffuses and escapes, poor ventilation may cause the combustible gas concentration in local air to approach or reach the lower explosive limit, which cannot be ignored.
④ When using combustible gas detectors, for media with a density higher than air, install the detector on the plane below the leakage point and take surrounding environmental features into consideration. Special attention shall be paid to the arrangement of safety monitoring points in areas prone to combustible gas accumulation.
⑤ Before using combustible gas detectors, identify all leakage points of equipment, analyze factors such as leakage direction and pressure, draw a layout diagram of probe positions, and classify risks into Grade Ⅰ, Grade Ⅱ and Grade Ⅲ according to leakage severity.
⑥ Based on the density of leaked gas and air flow patterns, develop a three-dimensional gas diffusion trend diagram, and formulate an initial layout plan for detection points at downstream positions of gas flow.
⑦ Determine the diffusion direction of combustible gas in case of massive leakage according to site-specific factors including wind direction and airflow.
⑧ Analyze whether the leakage is a slow seepage or jet-type leakage. For slow seepage, detection points shall be arranged close to leakage points; for jet-type leakage, points shall be set at an appropriate distance away. A final layout plan can be formulated after comprehensive assessment, so that the quantity and types of detectors to be purchased can be estimated.
