BS EN 751-3. Sealing materials for metallic threaded joints in contact with 1st, 2nd and 3rd family gases and hot water. Part 3. Unsintered PTFE tapes and PTFE strings|Gas pipes, Test equipment, Leak tests, Width, Water, Dimensional tolerances, Sealing materials, Testing conditions, Performance testing, Dimensional measurement, Instructions for use, Polytetrafluoroethylene, Hot-water supply systems, Screwed fittings, Vibration testing, Tape, Gas-powered devices, Thermal-cycling tests, Lubricants, Pressure testing, Classification systems, 2nd family gases, Test specimens, 3rd family gases, Determination of content, Temperature, Thermal testing, Pipe couplings, Pipe fittings, Metals, Dimensions, Wrapping tests, Pressure, Weight tolerances, Environment (working), Marking, 1st family gases