Product description:
PVC drainage and irrigation pipes are primarily made from sanitary-grade polyvinyl chloride (PVC) resin. The main material of PVC drainage pipes is, in fact, polyvinyl chloride itself. Commonly used PVC drainage pipes come in standard sizes with nominal outer diameters of: 32mm, 40mm, 50mm, 75mm, 90mm, 110mm, 125mm, 160mm, 180mm, 200mm, 250mm, 315mm, 400mm, 500mm, 630mm, etc. The typical length of PVC-U pipes is either 4 meters or 6 meters; other lengths are determined through mutual agreement between the supplier and the buyer.

Product advantages:
The pipe material boasts excellent surface hardness and tensile strength, a high safety factor, and outstanding resistance to aging. Its normal service life can exceed 50 years. The pipe exhibits excellent corrosion resistance against inorganic acids, alkalis, and salts, making it ideal for industrial wastewater discharge and conveyance. The pipe has a low friction coefficient, ensuring smooth water flow and minimizing the risk of blockages, thus requiring minimal maintenance. The material features a high oxygen index and self-extinguishing properties. Additionally, the pipe has a low linear thermal expansion coefficient—only 0.07 mm/°C—which results in minimal deformation even under temperature fluctuations. It also has a low thermal conductivity and elastic modulus, giving it superior frost resistance compared to cast iron drainage pipes. Pipe and fitting connections can be made using adhesive bonding, offering a simple construction method that is easy to operate and highly efficient in installation. The PVC-U pipe provides excellent watertightness: whether connected by adhesive bonding or rubber-ring joints, its installation ensures reliable water tightness. PVC drainage pipes represent an excellent alternative to traditional drainage materials, boasting superior physicochemical properties. Their inner walls are smooth, resulting in lower frictional resistance compared to conventional drainage materials; consequently, horizontal pipe installations can have shallower slopes, thereby increasing the net ceiling height within buildings. Moreover, PVC drainage pipes are significantly lighter—about one-fifth the weight of cast iron pipes—making them easier to transport and handle. Adhesive bonding simplifies both installation and maintenance, while their relatively low cost compared to conventional drainage materials substantially reduces overall project expenses. PVC drainage pipes exhibit strong corrosion resistance and are widely used in building wastewater, sewage, and rainwater drainage systems. Compared to cast iron and steel pipes, however, PVC-U drainage pipes have certain limitations: they have lower pressure-bearing capacity and weaker impact resistance. Furthermore, although PVC-U is a flame-retardant material, when used for exposed indoor piping, there remains a potential risk of fire spreading upward along the drainage riser.

Construction and burial requirements:
1. Before the subbase is constructed by the roadbed unit, horizontal drainage pipes in the median strip must be installed.
2. Trenching: Manually excavate trenches according to the design stakeout positions specified in the drawings and verified by surveyors. The width of the trench for PE pipes should be slightly wider than the pipe diameter—by about 1 to 2 centimeters—and the trench depth should be 23 centimeters below the subgrade surface. The trench length must extend 10 centimeters inward from the centerline on the inner side, while on the outer side it should reach the slope. In cut sections, the trench should extend to the inner wall of the roadside ditch. The trench slope must follow the road’s transverse drainage slope and must not be reversed; this ensures that water from the roadway is drained away from the subgrade. Before starting trench excavation, a guideline should be stretched to ensure straightness and alignment.
3. Connection: Both ends of each PVC pipe must be fitted with rubber rings and tightly secured to prevent leaks.
4. Lowering the pipe: After cleaning the bottom of the trench and connecting the pipes according to the trench length, place the pipes into the trench. At the end on the median strip side, tightly seal the opening with burlap sacks to prevent debris from entering the pipe and causing blockage.
5. Backfilling: Use the fine-grained soil excavated during the initial digging for backfilling, or alternatively, use sand. Be sure to remove any large stones. After backfilling, compact the material manually. The top surface of the backfilled soil should not exceed the subgrade level; it’s best if it is 1–2 centimeters below the subgrade surface. Otherwise, the soil may be compressed by vehicle traffic and lose its ability to drain water.
6. Cleanup: The remaining soil after backfilling must be promptly removed from the site, and the road surface must be thoroughly cleaned. Any excess soil from the PE pipes should be centrally unloaded at designated locations such as the borrow pit; it must not be dumped randomly on the roads.
7. After completion of the subbase construction in the fill section, on the well-prepared slope, cast-in-place trapezoidal outlet pads at the outlets according to the design dimensions. The pads shall be constructed using standardized wooden forms. Before pouring, the slope surface must be leveled and three 25-centimeter-long bamboo skewers must be driven into it to ensure stability.
8. Pay attention to ensuring that drainage pipes are installed at the lowest points of vertical curves along the route, so as to prevent water accumulation on the road surface. For high-superelevation pipe installations in embankment sections, after the subgrade has been inspected and accepted, promptly measure and stake out the positions of pipes and manholes according to the design drawings. Use manual labor in conjunction with small excavating machinery to trench the ground, ensuring that the bottom slope of the trench meets the design requirements for smooth drainage. The trench width shall not be less than the designed 47 cm, and any excavated waste shall be promptly removed from the site. In embankment sections, to ensure adequate backfill thickness above the pipe and prevent damage to the PVC pipe, lower the trench bottom by 20 cm. In high-superelevation roadbeds within rocky excavation sections, carry out reverse excavation only after the subbase layer has been completed.

Application
PVC drainage pipes have been increasingly widely used across various industries. The primary material of PVC drainage pipes is polyvinyl chloride (PVC), which boasts excellent heat resistance and corrosion resistance. For the purpose of enhancing the aesthetic appeal of building facades, indoor rainwater drainage systems are becoming ever more prevalent.