PVC Mixer Machine: Why Is Mixing Important Before Extrusion?
29 September, 2026
Standard solid-wall PVC-U drainage pipes are usually sufficient for buried pipes, horizontal branches, and projects where noise is not a major concern. Silent drainage pipes are more relevant to vertical stacks near bedrooms, hotel rooms, apartments, and other noise-sensitive spaces. However, pipe structure alone does not determine the final noise level. Pipe diameter, flow rate, fittings, brackets, shaft design, and installation quality also affect system performance.
Silent pipes in plumbing are specially designed drainage pipes that reduce the noise generated by wastewater flow, making plumbing systems quieter compared with conventional pipes.
| Feature | Standard pipe | Solid wall silent pipe | Hollow wall silent pipe |
| Pipe Wall Structure | Single-layer solid | Single layer + spiral ribs on the inner wall | Double-layer hollow cavity with 6-8 spiral guide ribs on the inner wall + spiral ribs on the inner wall. |
| Noise Reduction Principle | No noise reduction structure | Water flows freely down the pipe, impacting the spiral ribs on the pipe wall, guiding the water flow to spiral down along the wall. An air channel is left in the center of the pipe to reduce water impact noise. | The spiral guide + hollow interlayer double sound absorption blocks noise from being transmitted outward. |
| Noise Reduction Effect | High noise level, approximately 55- 60 dB | 8- 10 dB reduction, approximately 47- 52 dB | 10- 15 dB reduction, approximately 42- 48 dB, optimal noise reduction |
| Drainage Capacity | Regular Flow Rate | Riser water flow capacity increased by approximately 1/3, better venting, lower negative pressure in high-rise buildings | Water flow capacity superior to ordinary pipes, best resistance to negative pressure |
| Application | Riser pipes, horizontal pipes, buried pipes, rainwater pipes | Suitable only for drainage risers; not recommended for horizontal pipes. | Riser pipes for high-rise residential buildings, hotels, and apartments; suitable for noise-sensitive projects. |
| Disadvantages | High flushing noise | High negative pressure in high-rise buildings means horizontal pipes have no noise reduction effect; Fitting fittings must be matched and cannot be mixed with ordinary fittings; | High cost; Hollow core structures should be used with caution when buried underground, as they are susceptible to damage from compression. |
Important reminder: Spiral silent pipes only have a noise reduction effect on vertical risers. Using silent pipes on horizontal risers does not reduce noise or increase sound gain; horizontal risers should still use ordinary solid-wall tubes.
PVC silent pipes are essentially special PVC drainage pipes, which are divided into two types: solid-wall internal spiral and hollow-wall internal spiral; ordinary drainage pipes are solid-wall smooth PVC-U drainage pipes.
It adopts a double-layer structure design, forming a hollow layer on a traditional PVC pipe making machine, and incorporating spiral ribs on the inner wall of the pipe. Water no longer falls vertically but spirals downwards along the pipe wall, reducing water impact. The central air channel releases negative pressure in the riser, protecting the water seal of sanitary ware and reducing backflow odors and gas explosion noise. Its noise level is 30-40 decibels lower than ordinary PVC drainage pipes and cast iron pipes, creating a warmer and quieter living environment. The hollow layer also provides sound and heat insulation properties. To achieve the goal of reducing noise and creating a warmer and quieter working and living environment, this hollow spiral silencer pipe uses an inner and outer double-layer design with a vacuum layer in between. Six spiral ribs on the inner wall achieve double sound absorption, resulting in optimal performance!
This economical, silent riser pipe features a single-layer solid wall and only fluid flow guidance for noise reduction. Based on the PVC-U smooth-wall pipe extrusion process, several triangular spiral ribs are added to the inner wall of the pipe to achieve water vapor separation and spiral drainage. The drainage flow rate is approximately 5-6 liters per second.
1. Horizontal pipes, buried, low-rise buildings → ordinary PVC drainage pipes are better.
2. Riser pipes in high-rise residential buildings, with a limited budget → solid-wall internal spiral silent pipes are better.
3. Hotels/high-end apartments, with stringent noise requirements → hollow internal spiral silent pipes are better.
4. Replacing only the pipes without changing the fittings is not as good as using ordinary pipes directly.
