... ,cooling machine,4, plastic powder charger,5, conical double-screw extruder, 6,hadpiece, 7,double wall accordion pipe shaper,8, plastic pipe-expanding machine, 9 ... . It can be used to produce PVC PE plastic double-wall accordion pipes and plastic single-wall accordion pipes.main tech parameters:pipe diameter:90 ... - 0.6Mpa Gas-compression pressure:0.4-0.5Mpa conical double-screw extruder