参考文献 1.ISO.11922.1.1997.Thermoplastics、pipes for。the，conveyance。of,fluids,Dimensions、and、tolerances.Part,1。Metric.series、2.ISO、TR、10839,2000、Polyethylene、pipes、and fittings，for，the、supply。of,gaseous，fuels。Code，of。practice.for,design，handling and，installation 3 IEC 60529.2001。Degrees、of,protection、provided。by、enclosures、IP，code,4。EN、12117.1997、Plastics、piping systems Fittings.valves and.ancillaries Determination,of、gaseous，flow。rate，pressure，drop。relationships,5、IS0。12176 1 1998。Plastics。pipes.and,fittings、Equipment.for,fusion,jointing.polyethylene、systems，Part,1、Butt.fusion、6。IS0.12l76 2 2000 Plastics，pipes and.fittings.Equipment。for fusion，jointing、polyethylene.systems.Part.2 Electrofusion，7 EN。1555.3。2002 Plastics。pipimg,systems for，the，supply。of，gaseous，fuels.Polyethylene、PE、Part 3.Fittings