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