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