Polyethylene pipe fusion explained: How to Cut And Join PE Pipes?

Posted on: March 23, 2021 by Madison Pipe Industry, 4 min read

Cut a PE Pipe is easy, so is the connection. There are serveal connect method: hot melt, electrofusion connection, socket flexible connection, flange connection and steel-plastic transition joint connection.

How to Cut PE Pipes?

  1. Do not use mechanical or plasma methods for cutting.
  2. The grinding wheel cutting technology method can be used, or a special grinding wheel can be used during grinding.
  3. Use mechanical or manual methods to cut the PE pipe.
  4. Carbon steel pipes and galvanized steel pipes are more suitable for cutting with a hacksaw or mechanical methods.
  5. The cutting quality of PE pipe must meet the following requirements:
    1. The surface of the cut should be smooth, free of cracks, heavy skin, slag, oxide, iron filings, burrs, convexity and shrinkage.
    2. The deviation of the inclination angle of the cutting end surface should not be greater than 1 mm of the outer diameter of the pipe, and not greater than 3 mm, and the unevenness error should not be greater than 1 mm.

The above are some of the requirements for PE pipe cutting that we introduce to you. We must follow the standards when cutting the PE pipes to avoid cutting errors that affect the quality of the project.

How to Join PE Pipe?

Common connection methods for HDPE drainage pipes are: hot-melt connection, electrofusion connection, socket flexible connection, flange connection and steel-plastic transition joint connection.

1. Hot Melt Connection of PE Pipe

Hot-melt connection is a heating tool. After heating the PE pipe or pipe fittings to be connected under pressure to melt, remove the heating tool, apply pressure to connect the two melting surfaces together and keep it under a stable pressure for a period of time until the joint cools. Hot-melt connection includes hot-melt butt connection, hot-melt socket connection and hot-melt saddle connection.

Hot melt socket welding of HDPE drainage pipe:

  1. The hot melt machine can be used to take over after the power is turned on and the indicator light is on when the operating temperature is reached.
  2. Cut the pipe according to the required length, and the end surface of the pipe after cutting should be perpendicular to the pipe axis.
  3. Remove burrs and burrs on the cutting end face.
  4. The connecting end surface of pipes and pipe fittings should be clean, dry and oil-free. Use dry cloth or acetone to clean if necessary.
  5. Use a caliper and a suitable pen to measure and plot the socket depth at the pipe insertion end.
  6. Lead the pipe insertion end into the heating jacket without rotation, and insert it to the marked depth, and at the same time, push the pipe fitting to the heating head without rotation until it reaches the mark.
  7. After the heating time is reached, immediately remove the pipe and fittings from the heating head at the same time, and quickly and evenly insert them to the marked depth in a straight line without rotation.

2. Electrofusion Connection of HDPE Drainage Pipe

The electric fusion connection is to use the electric fusion pipe with embedded resistance wire to closely contact the connection part of the pipe to be energized, and the connection part is heated by the embedded resistance wire to integrate it until the joint is cooled.

Electrofusion connection can be used to connect with different types of pe pipes or socket pipes with different melt flow rates. Electrofusion connection is divided into electrofusion socket connection and electrofusion saddle connection.

3. HDPE Drainage Pipe Socket Type Flexible Connection

Polyethylene pipe socket type flexible connection is a new type of connection method developed by referring to the principle of socket type flexible connection of cast iron and polyvinyl chloride pipe (PVC-U). It is welded with a reinforced polyethylene at one end of the PE pipe Socket. The socket type flexible connection is to insert one end of the PE pipe directly into the special socket of the pipe or pipe fitting, and the locking ring in the socket is pressed to resist pulling out, and the rubber sealing ring is compressed and sealed to achieve the purpose of connecting the pipe and the pipe fitting.

The steps for flexible socket connection of HDPE drainage pipe are as follows:

  1. Cut the pipe according to the required length, and the end surface of the pipe after cutting should be perpendicular to the pipe axis.
  2. Remove the burrs and burrs on the cutting end face.
  3. Use a chamfering machine to pour the end of the pipe into 15°~30°, and the thickness of the groove is 1/2 to 1/3 of the wall thickness of the pipe.
  4. Use cotton yarn or dry cloth to clean the inside of the socket and the outside of the socket. If necessary, use a cleaning agent such as acetone.
  5. The depth of the socket of the pipe fitting minus 10mm is the insertion length of the pipe, and this length is used to mark the pipe.
  6. Check and adjust the rubber sealing ring. Use a brush to evenly apply the lubricant on the surface of the rubber sealing ring and the outer surface of the socket of the pipe or pipe fitting. It is forbidden to use butter or other oils as lubricants.
  7. Insert the socket of the pipe or pipe fitting into the socket of the pipe fitting to the marking line at a uniform speed. It must be vertical when inserting. If it is difficult to insert, assistive devices can be used.

4. Flange Connection of HDPE Drain Pipe

Flange Connection

Flange connection is mainly used for the connection of polyethylene pipes and metal pipes or valves, flow meters, pressure gauges and other ancillary equipment. Flange connections are mainly composed of polyethylene flange connections, steel or aluminum flanges, gaskets or sealing rings, bolts, nuts, etc. Flange connection is achieved by tightening bolts and nuts to make the flange connection and the flange sheet come into close contact.

5. Steel-plastic Transition Joint Connection of HDPE Drainage Pipe

The steel-plastic transition joint connection uses cold-pressed or other prefabricated steel-plastic transition joints to connect polyethylene pipes and metal pipes. The steel-plastic transition joint has a pull-resistant locking ring and a sealing ring, and it is usually required to have good sealing performance, pull-resistant and pressure-resistant performance than the polyethylene pipe in the system.

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