PVC (polyvinyl chloride) pipes have become the preferred material for building rainwater drainage systems due to their excellent physical and chemical properties and economy. The main advantages include:
Strong corrosion resistance: PVC pipes are not corroded by chemicals such as acids, alkalis, and salts, and are suitable for long-term rainwater transportation, especially for industrial areas or areas prone to acid rain.
Light weight and convenient construction: PVC pipes have low density, are easy to carry and install, and can reduce labor costs.
Smooth inner wall and high drainage efficiency: low friction coefficient, not easy to accumulate scale, can reduce the risk of blockage.
Strong pressure resistance: high-quality PVC pipes can withstand a pressure of 0.6MPa~1.6MPa, suitable for different buried or overhead drainage needs.
Economical: Compared with cast iron pipes and HDPE pipes, PVC pipes are cheaper and have a service life of more than 50 years.
1. PVC-U pipe (rigid polyvinyl chloride pipe)
Features: high rigidity, good weather resistance, suitable for building exterior wall rainwater pipes and underground drainage pipe networks.
Common specifications:
DN50~DN200 (for residential balcony and roof drainage)
DN250~DN400 (for municipal roads and community rainwater pipe networks)
Applicable standards: GB/T 5836.1-2018 (rigid polyvinyl chloride pipes for building drainage)
2. PVC-C pipe (chlorinated polyvinyl chloride pipe)
Features: high temperature resistance (up to 93℃), strong impact resistance, suitable for industrial plants or rainwater discharge in high temperature environments.
Common specifications: DN50~DN300
3. PVC-M pipe (modified polyvinyl chloride pipe)
Features: good toughness, strong impact resistance, suitable for earthquake-prone areas or drainage systems susceptible to external forces.
Diameter selection
Ordinary residential roof drainage: DN75~DN110
Commercial building rainwater drainage: DN160~DN250
Municipal road drainage: DN300 and above
Pressure level
Ordinary drainage: PN0.6 (0.6MPa)
Deep buried or high flow drainage: PN1.0~PN1.6
Connection method
Socket and spigot adhesive connection: suitable for pipes below DN110, simple construction.
Rubber ring socket connection: suitable for pipes above DN110, good seismic resistance.
Flange connection: suitable for large diameter (DN300+) or industrial drainage systems.
1. Installation precautions
Slope requirements: Horizontal pipes should maintain a slope of ≥2% to ensure smooth drainage.
Bracket spacing:
DN50~DN75: one bracket is set every 1.0~1.2m
DN110~DN160: one bracket is set every 1.5m
Expansion joint setting: Long-distance pipes (>4m) need to be equipped with expansion joints to prevent thermal expansion and contraction deformation.
{C}2. {C}{C}Common problems and solutions
|
Problem |
Cause |
Solution |
|
Pipe leakage |
Glue not applied evenly or joint not fully inserted |
Re-glue and ensure proper sealing at joints |
|
Poor drainage |
Insufficient slope or pipe diameter too small |
Adjust slope or replace with larger diameter pipe |
|
Pipe deformation |
Support spacing too wide or exposure to sunlight |
Add more supports or use UV-resistant PVC pipes |
3. Maintenance suggestions
Check the roof rain gutters regularly to prevent them from being blocked by leaves.
In cold areas, it is necessary to prevent ice from forming inside the pipes in winter, and an insulation layer can be added.
|
Pipe Type |
Advantages |
Disadvantages |
Suitable Applications |
|
PVC Pipe |
Low cost, corrosion-resistant, easy to install |
Poor UV resistance (requires protective layer) |
Building rainwater pipes, municipal drainage |
|
HDPE Pipe |
Good flexibility, impact resistant |
Higher price |
Underground pipelines, large drainage projects |
|
Cast Iron Pipe |
High strength, good fire resistance |
Heavy, prone to rust |
Renovation of old buildings |
PVC pipes are an ideal choice for rainwater drainage systems due to their economy, corrosion resistance, and ease of construction. When selecting pipes, it is necessary to select the appropriate pipe diameter and pressure rating according to the building type, drainage volume, and environmental conditions, and install them in strict accordance with construction specifications to ensure long-term stable operation of the system. In the future, with the development of modified PVC technology, its performance in high strength and weather resistance will be further improved, and its application range will be wider.
