In general, the noise in drainage process of the indoor drainage plastic pipeline of building is large, compared with common drainage tubing and cast iron pipe; the noise caused by the PVC-U noise-abating pipe with spiral tendon on inner wall is decreased obviously. Because the noise-abating principle is not only limited to sound insulation, but also to the reduction of noise which comes out during the drainage process.
 
In general situation, there is air in straight wall pipeline. The water flow from up to down compacts with the air of irregular motion, the velocity gradient and adhesion speed formed from the speed of the convective cell of the inner wall of pipeline, even if at the steady flow condition, it will give off some water sound, if the 搘ater hammer?and so on is caused by outside reason, the noise will reach with that, under some condition, some water flow noise can be generated by complex factors such as the changing of the water flow direction and flow speed etc.

It is possible to decrease the noise by changing the structure of the tubing inner wall according to the basic reason of the water noise in the straight wall pipe. If the tubing inner wall is made to appear spiral roll form beading structure, forcing the water flow spiral flow down along inner wall of the tubing, decreasing the compaction of the water flow and air, adjusting the flow direction of liquid, decreasing the 搘ater hammer?affection, can decrease the noise of the water flow. The spiral tendon structure of the inner wall of the PVC-U noise-abating makes the drainage spiral form the best drainage condition, at the same time, the ventilation ability of the drainage pipeline is improved greatly, and the drainage noise will be decreased with that, so the noise-abating pipe is better than the straight wall pipe.

PVC-U spiral noise-abating pipe is designed according to above principle, the water flow direction and flow forms can be changed to realize noise-abating through changing the structure of the tubing inner wall, this kind of tubing has potential market in indoor drainage. It has three forms, solid wall spiral noise-abating pipe, with the convex tendon added in the inner wall of the PVC-U building drainage pipe;  PVC-U new composite spiral noise-abating drainage pipe, with the convex tendon added in the inner wall of the PVC-U new composite drainage pipe;  PVC-U double walls hollow inner spiral noise-abating pipe, it makes inner wall of pipe appear spiral convex tendon based on the PVC-U hollow wall pipe.

 S0 S1 S2
Ring Stiffness KN/㎡ ≧2.5 ≧4.5 ≧8
Apparent Density G/m3 0.9-1.3
Composite Test No Breakage, No Desquamating
Hammer Dropping
Impact Test (0℃) No Breakage, No Desquamating
Vertical Shrinkage Rate ≤5%   No Breakage, No Desquamating
Dichloromethane Immersion Test The inside and outside surface should not be less than 4L

3.Special Patented Products of Ginde PVC-U Spiral Noise-abating Pipeline System

The PVC-U solid wall spiral noise-bating pipe .
The structure performance of the PVC-U solid wall spiral noise-bating pipe is that the inner wall of the pipeline shows the spiral tendon with many sections as the triangle, the tendon highness is 1~3.5mm, these tendons fall in spiral form with special curve of about 50mm. The tubing specification of the PVC-U solid wall spiral noise-bating pipe is D. It is expressed by (Nominal outside diameter)(nominal wall thickness) (tendon highness).