What are the connection methods of PE pipes?
There are many connection methods between polyethylene pipes and pipes, pipes and PE pipes, pipes and fittings, and polyethylene pipes and metal pipes. Different connection methods have their own advantages and limitations. Users can choose according to the pipe diameter and working pressure. , place of use and other environments, select the appropriate connection method. The most commonly used connection methods for urban water supply polyethylene pipes are: hot-melt connection, electric fusion connection, socket-type flexible connection, flange connection, steel-plastic transition joint connection, etc.
1.Hot melt connection
The hot-melt connection is to use a special heating tool to heat the part of the polyethylene pipe or pipe fitting to be connected under pressure, and after it is melted, remove the heating tool, apply pressure to connect the two melting surfaces together, and keep it under a stable pressure. for a while until the joint cools down. Hot-melt connections include hot-melt butt connections, hot-melt socket connections, and hot-melt saddle connections.
2.Electrofusion connection
Electrofusion connection is to use the special electrofusion pipe fitting with embedded resistance wire to closely contact the connection part of the PE pipe or pipe fitting for electricity. The PE pipe heats the connection part through the embedded resistance wire to melt and connect it until the joint cools down. Electrofusion connections can be used to join different types of polyethylene pipe or socket fittings with different melt flow rates. Electrofusion connection is divided into electrofusion socket connection and electrofusion saddle connection.
3.Socket type flexible connection
The socket-type flexible connection of polyethylene pipes is a new connection method developed by referring to the principle of socket-type flexible connections between cast iron pipes and polyvinyl chloride pipes (PVC-U). PE pipes are welded on one end of polyethylene pipes with a reinforced Polyethylene socket. The socket-type flexible connection is to insert one end of the polyethylene pipe directly into the special socket of the pipe or pipe fitting, and compress the locking ring in the socket to resist pulling out, and the rubber sealing ring to compress and seal, so as to achieve the purpose of connecting PE pipes and pipe fittings .
4.Flange connection
The flange connection is mainly used for the connection of polyethylene pipes and metal pipes or valves, flow meters, pressure gauges and other ancillary equipment. The flange connection is mainly composed of polyethylene flange connectors, steel or aluminum back pressure loop flanges, steel or aluminum flanges, gaskets or sealing rings, bolts, nuts, etc. The flange connection is to achieve the purpose of connection by tightening the bolts and nuts so that the flange connection parts and the flange pieces are in close contact.
5.Steel-plastic transition joint connection
The steel-plastic transition joint connection is to use the steel-plastic transition joint prefabricated by cold pressing or other methods to connect polyethylene pipes and metal pipes. There are pull-resistant locking rings and sealing rings in the steel-plastic transition joint, which are usually required to have good sealing performance, pull-out resistance, and pressure resistance that are greater than those of polyethylene pipes in the system.
The above is the connection method of PE pipes. It should be noted that it is strictly forbidden to directly make pipe threads on polyethylene pipes and fittings in any form, and use threaded connections; it is strictly forbidden to use open flames to bake polyethylene pipes and fittings for direct connection.
With the development of PE pipes to this day, the connection technology of polyethylene has been very mature and reliable. Statistics show that the leakage rate of polyethylene pipes is less than 2/100,000, which is far lower than 2-3% of ductile iron pipes, which greatly improves the safety and economic benefits of pipelines. Very important reasons for using polyethylene pipe.
