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