The welding and installation methods of PE pipes are usually divided into two types: electrofusion welding and hot-melt welding. Hot-melt welding is easier to operate and has higher welding quality than electro-fusion welding. Today we will introduce to you the complete operation method and precautions of using a hot melt butt welding machine
to connect PE pipes.
Requirements for PE pipe connection
1. Before pipeline connection, the pipes, fittings, and ancillary equipment should be checked according to the design requirements, and visual inspection should be carried out on the construction site, and they can be used only if they meet the requirements. The main inspection items include pressure rating, outer surface quality, fit quality, material consistency, etc.
2. Corresponding special heating tools should be used according to different interface forms, and open flames should not be used to heat pipes and fittings.
3. Pipes and pipe fittings of the same grade should be used for pipes connected by welding. For those with similar properties, must be tested first and then qualified.
4. Pipes and fittings should be placed at the construction site for a certain period of time before connecting so that the temperature of the pipes and fittings is consistent
5. When connecting in cold climates (below 5 degrees) and strong wind conditions, protective measures should be taken or the connection process should be adjusted.
6. The end of the pipe should be clean when the pipe is connected, and the mouth of the pipe should be temporarily blocked at each end of work to prevent debris from entering the pipe.
7. Visual inspection should be carried out after the pipeline connection, and those who fail to pass should be reworked immediately.
Hot melt butt steps
When using this method to connect, a hot-melt butt welding machine is used, and the main operation steps are as follows
1. After the debugging of the butt welding machine is completed, place the pipe material to be placed on the fixture of the welding machine and clamp it.
2. Clean the end of the pipe to be connected and use a planer to mill the connecting end face to straighten the two butt joints so that the dislocation is not greater than 10% of the wall thickness of the pipe.
3. After the temperature of the heating plate reaches the set required temperature, put it into the heating plate for heating.
4. After the heating is completed, take out the heating plate, quickly start the oil pump pressure to join the heating surfaces of the two pipes, and increase the pressure to the welding pressure to maintain pressure and cool.
5. After cooling to the specified time, open the fixture and remove the pipe from the frame, observe the curling to determine the quality of the connection, and the connection is complete.
Method for checking the quality of butt fusion
1. The determination of the quality of hot melt butt joints is still mainly based on the non-destructive appearance inspection of the welding seam. Usually includes a visual inspection of the bead geometry and inspection of cutting the bead, buckling the bead back to confirm the connection for lack of fusion.
2. Ultrasonic testing and X-ray testing have applications abroad.
3. Destructive detection. Tensile tests, bending tests, tensile creep tests, etc. were carried out on the cut joints.
Precautions for hot melt butt
1. Must abide by the procedures and precautions for the use of docking equipment.
2. Operators must wear gloves and work clothes to protect themselves from electric shock or burns.
3. Heating the surface of the board, the connecting end surface of the connector should be kept clean.
4. The docking pressure should be debugged into the actual required value of the field connection.
5. Polyethylene pipes cannot be heated with an open flame.
6. Protect the interface from sand and rain when welding
Important process parameters of hot melt butt fusion
1. The temperature of the heating plate refers to the surface temperature of the heating plate, which is generally measured with a surface thermometer. When measuring temperature, the influence of ambient temperature should be considered. (except the equipment has been considered) The temperature of the hot plate should not only ensure that the end face of the pipe melts rapidly but also ensure that the welded pipe fittings will not be degraded due to excessive temperature.
2. The welding pressure, pressurization, and heating pressure are equivalent to the melting butt pressure. The function is to force the heating of the pipe, remove the uneven part of the end face of the pipe so that all the end face of the pipe is in contact with the heating plate and heated evenly.
3. The curling height is used to measure the time that the heating pressure acts on the pipe section, that is, the degree of pressure heating.
4. The endothermic pressure is about 1/10 of the melting butt pressure. Its main function is to prevent the pipe from rebounding, so that the pipe is close to the heating plate, improving the heating effect and reducing the heating time. The time of the heating stage is related to the cross-sectional area of the welded pipe, the temperature of the heating plate, and the ambient temperature.
We should pay attention to setting the heating plate temperature according to the welding process parameters given by the welding machine. If it is an automatic welding machine, parameters such as heat absorption time and cooling time should also be set.
As a professional manufacturer of butt fusion equipment
, we have accumulated rich design and production experience in this field. We have a professional production team and a complete management system, and strictly control the quality of every detail of the product. At the same time, we will provide effective solution technology and thoughtful one-stop service according to the diverse needs of customers. If you want to buy our hot melt butt fusion machine, please contact us immediately!