Explore drainage pipes, various fittings and connection methods

Overflow water or drainage from containers and equipment such as drinking water storage tanks, food preparation and washing equipment in the kitchen, and air cooling towers shall not be directly connected to sewage pipes. Indirect drainage should be adopted, and inspection wells or broken pipes can be used for handover.

Drainage pipe fittings are primarily used to connect different pipes to ensure that sewage, wastewater, and other unwanted liquids can drain smoothly from a home or building, preventing accumulation of water and potential water damage.

It is a thermoplastic plastic pipe made of high-density polyethylene resin and extrusion molding process for use without internal pressure. It has the advantages of corrosion resistance, aging resistance, impact resistance, and crack resistance, such as corrugated pipe.

Suitable for drainage pipes in high-rise buildings over 100 meters tall, as well as locations with high building standards and a quiet environment. For buildings over 100 meters tall, drainage risers should use flexible joints. For drainage risers over 50 meters tall, or for high-rise buildings in areas with a seismic fortification rating of 8 degrees, flexible joints should be installed on every two floors of the riser. In areas with a seismic fortification rating of 9 degrees, flexible joints should be installed on both risers and transverse pipes.

The drainage cast iron pipe uses rubber sealing rings and is fastened with bolts. It has good flexibility, elasticity, sealing and seismic resistance, and is easy to construct.

It has good compressive strength and durability and is suitable for drainage pipes that bear heavy loads, such as urban drainage mains.

Featuring corrosion resistance, light weight, and ease of handling and installation, PVC-U plastic pipes are widely used in indoor and outdoor drainage piping for industrial and residential buildings. However, their disadvantages include low strength, poor temperature resistance (operating temperature ranges from -5°C to +50°C), large linear expansion, high pipe noise, susceptibility to aging, and poor fire resistance. Plastic pipes are commonly joined using socket-and-spigot bonding or welding.

When using PVC-U plastic pipes for drainage, special care must be taken to minimize temperature-related expansion and contraction. Expansion joints are often installed to address dimensional deviations during installation.

Suitable for smaller diameter PVC-U pipes, typically under 50mm. A special solvent-based adhesive is used to bond the connecting surfaces of the pipe and fitting. The adhesive penetrates the surface of the PVC-U material, forming a strong chemical bond.

For larger diameter PVC-U pipes, elastic sealing rings are commonly used. A groove inside the fitting accommodates the sealing ring. Once the pipe is inserted into the fitting, the sealing ring provides a strong seal. It is easy to use and allows for a certain degree of angular misalignment. It is suitable for pipes with diameters over 50mm.

Flange connection is used in applications where frequent disassembly or connection to other pipe materials is required. Flanges are welded or bonded to each end of the PVC-U pipe and fitting, and then bolted together. This connection is suitable for piping systems operating under high pressure or in special environments.

Although PVC-U pipes are not inherently threaded, threaded connections can be achieved by installing threaded fittings on the pipe ends. This is suitable for applications where connection to metal pipes or other threaded equipment is required.

Suitable for HDPE drainage pipes, it consists of a hydraulically operated control console, welding frame and fixture, electric heating plate, and electric milling cutter. During welding, a mica ferrule is used to hold the pipe in place. The pipe and fitting are heated under pressure. Once the heat-melting temperature is reached, the heating tool is removed and pressure is applied to bring the two molten surfaces together. The pressure is maintained for a period of time until the joint cools. This process is fully computer-controlled.

One end of the pipe is directly inserted into a specially designed socket of the pipe or fitting. A locking ring inside the socket provides compression and pull-out resistance, while a rubber sealing ring provides a tight seal, achieving the desired connection. This connection offers advantages such as a non-rigid connection, excellent shock resistance, and removable assembly and assembly, making it easy to maintain.

An electric fusion fitting with an embedded resistance wire (usually copper) is brought into close contact with the pipe at the joint. Current is applied, heating the joint through the embedded resistance wire, melting it into a single piece, until the joint cools.

Quick to install and removable, they require no maintenance or replacement throughout their lifecycle, with a service life of over 50 years. They are suitable for connecting HDPE drainage pipes in high-rise buildings, five-star hotels, high-end residential buildings, hospitals, chemical plants, laboratories, and other locations.

Suitable for flexible joints of mechanical cast iron drainage pipes. This joint is preferred for concealed or relatively concealed pipe installations. Clamp joints can also be used for exposed installations and where visual appeal is a concern. Flexible flange and spigot joints are preferred for buried cast iron drainage pipes.