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