城市燃气的技术标准(德国).ppt

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * DVGW Technical Rules on Gas Pipeline InspectionDVGW关于燃气管线检测的技术标准 Scope-适用范围 Mobile devices to手持式检测仪是指： detect installation leaks—检测燃气设施的泄漏 (public gas distribution and customer installations) on installations designed to transmit gases in accordance with G 260. Assessment of risk of explosion. Determination of specific gas components G 465-4 DVGW Technical Rules on Gas Pipeline InspectionDVGW关于燃气管线检测的技术标准 Instrumentation for natural gas Note: Explosion protection required for devices used as mobile gas alarms and/or in areas with explosive gas-air mixtures or where such mixtures are expected 1) Calibration gas fed into the device including the system of probes must reach its concentration within 10s. Service case Principle of action Measuring range Minimum instrumental sensitivity Signal Calibration gas Frequency Surface inspection of buried gas pipelines FID gas-sensitive semi-conductor 1 – 20,000ppm CH4/C3H8 1ppm combustible gas freely adjustable; e.g. 10ppm 10ppm CH4 1) Sensitivity tests before start of work; after interruption of work, if necessary (cf. also G 465-1, 4.1) Inspection of bare gas pipelines, gas pressure regulator stations, natural gas filling stations, natural-gas driven vehicles, installation lines gas-sensitive semiconductor FID 1 – 20,000ppm CH4/C3H8 1ppm combustible gas concentration-dependent acoustic signal; fixed signal at end of measuring range 1 Vol.-% CH4 ultra-sound qualitative 30l/h combustible gas/inert gas (distance between gas pipeline and device ≤ 10m) Inspection of ground air, air in sewers, pits, change of gas type (commi-ssioning and de-commissioning of gas pipelines) thermal conductivity sonic speed 0.1 – 100 Vol.-% CH4/C3H8/CO2 0.1 Vol.-% combustible gas 100 Vol.-% CH4 Weekly to 6-monthly indication sensitivity tests, depending on service availability Inspection of indoor air, air in pits and sewers for reaching the LEL threshold g