RISER TUBE FOR CONNECTION WITH GAS PIPING

摘要

PROBLEM TO BE SOLVED: To prevent a gas leakage outbreak even when a riser resin tube in a protecting tube is melted down by encountering with a fire-hazard by any chance. SOLUTION: A bottom end of a metallic conduit connected to a ground-based gas meter and the upper end of a riser resin tube 7 of thermoplastic resin connected to a resin pipe 5 buried underground are jointed together by a rise pipe fittings wherein the riser resin tube 7 is erected from underground to ground surface and the external surface of the riser resin tube 7 is covered with the protecting tube 8. A burial depth D underground of the protecting tube 8 is selected to be not less than 80 mm, and more preferably to be not less than 90 mm. Thereby, in the even of a fire-hazard causing a meltdown of the riser resin tube 7 by the generated heat transmitted thereto through the protecting tube 8, since the riser resin tube 7 is melted down within the underground burial depth D of the protecting tube 8 resulting in the blockage of the tube, gas leakage from the riser resin tube 7 can be prevented.