Abst：The common connection methods of hdpe drain pipe are: electrofusion connection, socket hot melt connection, sealing ring socket connection, hot melt butt joint and groove type clamp connection, butt welding connection and electric welding pipe coupling connection. These connection methods each have their own performance characteristics, and the use and installation are not the same.
hdpe drain pipe common connection methods are: electrofusion connection, socket hot melt connection, sealing ring socket connection, hot melt butt joint and groove clamp connection, butt welding connection, electric welding pipe coupling connection , socket type casing connection with sealing ring, threaded connection method, linear expansion socket tube connection, flange connection method.
These connection methods have their own performance characteristics, and the use and installation are not the same.
1, Hot-melt connection (that is, the material of the same material pipe is melted into one after high temperature)
1. Hot-melt butt joint: the connection method of heating the two pipes through the heating plate and butt welding together
Advantages: Simple operation, high strength, stable connection quality and fast construction.
2. Heat shrinkable tape (set) connection: double-layer connection, heat shrinkable tape (set) made of polyolefin and reinforcing fiber after cross-linking, inner layer adopts heat shrinkable tape as sealing layer, outer layer as reinforcement Layer to ensure the tightness and strength of the joint.
Advantages: Strong anti-aging ability, good sealing, strong tensile resistance, suitable for poor geological environment.
Second, Electric hot melt connection
1. Socket type electric hot-melt connection: (Some direct sockets and sealing rings are not subjected to material heating change) Pre-fabricated sockets and sockets before the pipe is delivered, and embedded in the inner wall of the socket, connecting When a special electric welding machine is used to energize the electric resistance wire, the electric resistance wire heats up to melt the joint portion, and the resin on both sides of the electric resistance wire interface is connected under the action of the resin melting pressure, and is cooled to achieve the connection purpose.
Advantages: Good sealing, high sealing strength, uniform joint strength and pipe strength. Applicable to projects with good geological conditions or low pressure requirements for water delivery.
2. Electric hot melt belt connection: The principle of electric hot melt belt connection is the same as that of socket electric heat melting. The difference is that the joints of the two pipes are flat, which is similar to the shrinkage belt connection. The difference is that only the electric hot melt belt is tight. An electric heating element is added to the wall of the pipe to heat and melt the hot melt belt and the outer wall of the pipe joint.
Advantages: Easy installation and installation, low cost, high construction efficiency, secure sealing of joints, no leakage, good shear resistance .
Three, Clamp connection
Clamp-type elastic connection: This connection integrates rigid connection and flexible connection, the inner layer is sealed, and the outer layer is made of stainless steel clamp to increase the strength of the interface.
This type of connection is suitable for engineering in various environments. It is not affected by the groove water level on the construction site. It is convenient for maintenance and repair, but it requires a high degree of responsibility from the construction personnel. The material factor should be relatively high. .
four. Welded connection
Butt joints are available for all pipe diameters from φ 32-315mm. The performance characteristics of the connection method are: rigid connection, non-removable, and tensile strength.
butt weld connection is one of the simplest method of pipe fitting. It provides many convenient and preconditions for the prefabrication of the entire system without the need for additional components. Thus, the butt weld connection can be used either on site or in the shop.
The welding cross section of the
butt weld is small, the weld edge does not interfere with the pipe, and there is no change in the internal section of the pipe. The allowable thickness of the welded surface is almost the same as the thickness of the pipe wall, so the pipe is not wasted. Through the butt joint method, the length of the pipe and the joint of the elbow can be fully utilized.
pipe diameter <φ 75mm can be manually welded; welded by electric welder, the diameter of the pipe is generally φ 40-315mm.
five. Electric welded pipe coupling connection method
Electric welded pipe hoop connector connection method is suitable for pipe connection from φ 40-315mm. Its performance characteristics: rigid connection, non-removable, tensile strength.
Electric welded pipe clamp connector connection method is usually used for on-site welding, modification, supplementary installation and repair because it is easy to use, reliable, simple and quick to connect. If the piping system needs to be modified or made some early modifications, the welded pipe hoop can be slid by removing the middle stop ring.
The heating zone and the melting zone of the welded pipe hoop are separated, so there is no resistance in the center of the pipe clamp, so it is safe to use. After the welding work is completed, the resistance coil is coated with PE (polyethylene) material, so it will not be corroded.
The pressure value required for welding is generated by the shrinkage of the pipe clamp during heating. When heated, the pressure is evenly distributed on the weld surface, and the shrinkage causes the pipe diameter to vary within the allowable range.
six. Socketed short tube connection method with sealing ring
The socketed short pipe connection method with sealing ring is suitable for pipe connection from φ 32-160mm. Its performance characteristics: non-rigid connection, removable, tensile strength.
Socketed short tube connectors with seals are commonly used for assembly between various simple prefabricated fittings and can be mounted horizontally or vertically during assembly. This flexible small-size connection method has certain advantages when the installation space is limited. The connector also comes with a yellow protective cap to prevent the entry of trash during the unfinished phase of assembly.
Also pay attention to the installation, first cut the end of the pipe into 15 & deg;, then lubricate the surface with soft (potassium) soap, silicone or petroleum jelly. It is strictly forbidden to lubricate with mineral oil or grease to avoid damaging the rubber seal. In addition, the socket is not used as a dilator, so the fitting must be fully inserted into the socket.
seven. Threaded connection
threaded connection method is suitable for pipe joints from φ 32-110mm. Its performance characteristics: non-rigid connection, removable, tensile strength.
threaded connection method is commonly used in a variety of prefabricated installations where it is easy to remove the connector, as well as connection to the sewer trap and shower tray. When installing, the threaded parts must be pressed with a sealing ring so that only a small surface area of the sealing ring is in contact with the water for better connection.
eight. Socket-type telescopic short tube connection method
Socket type telescopic short tube connection method is suitable for pipe connection from φ 32-315mm. Its performance characteristics: non-rigid connection, removable, tensile strength.
Installing the socket type telescopic short pipe joint must be fixed with an anchor pipe clamp to prevent the position of the socket from being moved during thermal expansion and contraction. At least one socket type telescopic short tube must be installed on the vertical riser between the floor and the floor, on the long-distance collection pipe network, and on the buried pipe. This is because the socket type telescopic short tube not only eliminates the thermal expansion and contraction caused by the temperature change of the drainage process, but also helps to connect with the various floor branch pipes, making the pipe installation simpler.
9. Flange connection method
flange connection is suitable for pipe connections from φ 50-315mm. Its performance characteristics: non-rigid connection, removable, tensile strength.
flange connection method is usually used as a detachable connection on low-pressure conveying lines (factory, water pump, liquid storage tank, swimming pool). In addition, the flange connection method is also the simplest connection method between cast iron pipe and steel pipe. The flange blind plate can be used to inspect the opening of the port.
10. HDPE tube anti-telescoping sleeve
Anti-telescoping sleeves are suitable for pipe connections from φ 50-315mm. Performance characteristics of the connection method: rigid connection, non-removable; tensile strength.
It is a convenient method to use anti-telescoping sleeves for the connection of irregular, irregular and special pipes. Typically this method can also be used to connect HDPE tubes to a variety of different ceramic equipment, such as laboratory wash tanks.
When installing, first put the special rubber ring on the end of the pipe end, make sure that the rubber band is placed at half the length of the casing. Then insert the pipe into the casing and push it in firmly. Continue to move the torch or soft light and use a low temperature (about 125 ° C) to evenly heat the casing around. After the above treatment, the sleeve will shrink, so that the connector is more secure and sealed. Finally, the anti-telescoping sleeve is fixed by the anchor pipe clamp.
The characteristics of the project are different according to the pipeline; The general hot-melt connection method is simple for construction and is suitable for non-pressure drainage and small-diameter pipelines. The large-diameter pipeline is heated due to the heavy weight of the pipe itself. Large area, long warm-up time, inconvenient movement and other drawbacks, it is recommended to use the connection operation professional, high efficiency and good sealing of the electric hot-melt connection and clamp connection.
In addition to the above factors, the connection method of the
pipeline will be affected by geological effects. The uneven settlement of the collapsed land due to the ground will cause the pipe joint to stretch at the pipe itself and the gravity of the pipe. It is recommended to use flexible connection. : Optional heat shrinkable tape (set) connection, electric hot melt ribbon connection, or socketed connection with sealing ring.