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