Plastic bellows should look smooth, uniform color, inside and outside the walls of the spacer does not allow broken, scratched bubbles, cracks, lumps and affect use. Corrugated plastic pipe ring stiffness of not less than 6kN / m2 corrugated plastic pipe to withstand the lateral partial load, the pipe surface should not be broken; 5min after unloading residual deformation of the pipe shall not exceed 10% of the pipe diameter. Corrugated plastic pipe bending method prescribed after repeated bending of five dedicated plug able to pass, the flexibility from a qualified plastic corrugated plastic wave tube. Plastic bellows vacuum low-temperature impact hammer impact test TIR maximum allowable rate is 10%. Plastic bellows connection can take a long plastic welding machine plastic pipe are welded together or the use of mechanical connections. Mechanical connection in the form of contacts were examined, including the pipe and the pipe connecting the connection pipe connecting the head pipe and connected to the anchor plate, three types of the exhaust pipe and pipe connector connected to the exhaust pipe. Prestressed plastic corrugated pipe is flexible, high ring stiffness, not afraid to step on the pressure, can not easily be broken tamper chisel.