DN300 SN8 carat pipe, dedicated to municipal community drainage

In the construction of municipal drainage and community underground pipe network, the ring stiffness and long-term operation reliability of the pipe directly affect the service life of the entire drainage system. As a common specification of high-density polyethylene wound structure wall pipe, DN300 SN8 carat pipe is gradually becoming the preferred solution for urban rain and sewage diversion, community drainage outlet pipe and municipal branch pipe engineering.

DN300 represents a nominal inner diameter of 300mm. This caliber can match the drainage flow demand of most multi-storey residential quarters and municipal branches. It will not cause waste due to excessive pipe diameter, and can also meet the flow capacity under the design fullness. SN8 indicates that the ring stiffness of the pipe reaches 8 kN per square meter, which belongs to the higher ring stiffness grade. In the laying environment with large covering depth, dynamic load or high groundwater level, SN8 grade can effectively resist external pressure deformation, maintain the stability of the pipe wall structure, and avoid leakage or poor drainage caused by excessive radial deflection.

The structural feature of the carat pipe is that its pipe wall is formed by spiral winding of high-density polyethylene strip. The outer wall of the pipe has a reinforcing rib structure, and the inner wall is smooth and flat. This special-shaped section design effectively reduces the amount of material per unit length while ensuring the ring stiffness, so that the pipe has the advantages of both light weight and high strength. The smooth inner wall reduces the water flow resistance, the roughness coefficient is much lower than that of the concrete pipe, and it is not easy to scale in long-term operation, which helps to maintain the water cross section of the drainage system.

In municipal district drainage applications, the connection method of DN300 SN8 carat pipes is usually socket-type electrofusion connection or sealing ring socket connection, and the interface is tight, which can adapt to a certain degree of axial deflection and uneven foundation settlement. During construction, a gravel cushion needs to be laid at the bottom of the trench and the degree of compaction is strictly controlled. The backfill material on both sides of the pipe and within a certain range above the top of the pipe should be medium coarse sand or gravel soil, layered symmetrically compacted, and avoid direct use of heavy machinery for rolling. These measures can give full play to the design advantages of SN8 ring stiffness to ensure that the pipe and the surrounding soil form a good pipe-soil interaction system.

From the perspective of engineering economy, the DN300 SN8 carat pipe is lightweight and flexible in single section length, which can reduce the number of hoisting equipment and joints and speed up the construction progress. Its excellent chemical corrosion resistance, insensitive to common acid, alkali and salt components in domestic sewage, no additional anti-corrosion treatment is required, and the maintenance cost of the whole life cycle is reduced. Under the premise of strict implementation of design and construction specifications, the pipe can provide a safe, durable and low-leakage conveyor channel for the municipal community drainage pipe network.