PE butt fusion hydraulic welding machine for Brazil

The butt fusion machine for brazil main operations include:

Overview of butt fusion Operation

For butt fusion plastic pipes (PE, HDPE, PP, MPP, PVDF), the butt fusion operation is to heat the two pipe end faces to a certain temperature, and then apply a certain force to fuse them together. When the end face of the tube is heated, the molecular structure changes to an amorphous state. When butt pressure is applied, the resulting pressure causes the molten material to flow and mix, the plastic molecules are mixed together, and after the joint cools, the molecules return to the solid state, and the joint and tube become a complete structure. The result is a strong, fully sealed connection.

Use and maintenance of Butt fusion welding machine

The cutter blade is sharp, do not get too close to the cutter when the cutter is running. When replacing the blade, the power should be cut off first to ensure that the machine will not be turned on by mistake.

The hot plate is hot and can damage clothing and burn skin. When not in use, please put the heating plate in a special bracket (basket), and avoid direct contact with your body during operation.

If the power switch is damaged, do not use the butt welder, and be sure to replace the switch before use.

Repair butt welding machine and accessories: Check whether the moving parts can move normally without jamming. Parts for breakage or any other conditions that may affect operation. If damaged, the machine should be repaired before use, many accidents are caused by poor machine maintenance.

Quality problems of butt fusion welding for Brazil interface

There are many quality problems such as asymmetric curling, excessive misalignment, bubble depression and pitting on the surface of the welding seam. Reasons for the above problems include:

1. In order to save equipment cost, semi-automatic welding machine is used and welding is not performed according to the specified welding parameters, such as excessive driving pressure of welding machine and short cooling time;

2. Use automatic welding machines with unqualified welding performance;

3. Due to the different properties of PE pipes (such as thermal stability) of different manufacturers, the parameter settings of the hot-melt welding machine are not consistent with the characteristics of the pipes;

4. Use mismatched pipes for welding, such as butt welding of PE80 and PE100 materials;

5. In order to catch up with the construction period, the construction personnel will construct under severe weather conditions such as humidity;

6. The specified hot-melt fixture and roller bracket are not used during welding, and the quality of the counterpart does not meet the requirements;

7. Welding machine operators are employed without professional training and without certificates.

In the process of pipeline construction, due to the limitation of the construction site, PE pipe fusion may be required. For example, the pipe jacking may be welded with a length of tens of meters or hundreds of meters, and poor welding will affect the construction quality, cause water leakage, and affect the construction. schedule.

PE pipe butt fusion welding method and steps:

PE pipe counterpart

1. Fix the PE pipes and pieces to be welded on the docking machine, and use the fixture according to the size of the pipe. Use a brush and a cotton cloth to remove the oxide layer, oil and dust from the nozzle.

2. The connecting ends of the two parts to be connected should extend out of the welding fixture for a certain free length, and the two corresponding parts to be connected should be aligned so that they are on the same axis. The wrong side should not be greater than 10% of the wall thickness.

3. The end face is planed with a milling cutter to make the butt end face smooth, flat, clean and vertical. Note: The milling cutter should be started first, and then the feed handwheel should be slowly turned. When continuous cutting occurs, the milling cutter disc should be removed, and the two butted pieces should be straightened by adjusting the tension of the clamp (turn the pipe if necessary).

Endothermic stage

The heating plate automatically heats up until the green indicator light is on or reaches the set temperature, and the pipes and fittings to be welded are closed to heat the end faces. Separate the PE water supply pipes and fittings from the heating plate, and then close the two heating end faces and butt them together. (See endothermic timetable) The two heated nozzles are melted. When heated to a molten state, the endothermic process is completed. When the ambient temperature is 20°C, the heating time is specified at 10×thickness (mm) seconds, and the height of the flat bump on the welding surface is required to reach the required value. Note: At this stage, the flanges that meet the specified requirements are enough, and the pressure can be maintained to absorb heat. Can't keep increasing the pressure!

Removing the electric heating platen

When the endothermic process is completed, the electric heating plate is removed and the pressure is quickly started, and the operation is completed within 10 seconds: especially when the ambient temperature is low, it is shortened as much as possible, the end face is cooled very fast, and the connection speed is slow, which directly affects the quality of welding.

Cooling interface

After the interface is completed, the counterpart should be stabilized on the fixture and allowed to cool naturally. Generally speaking, the small diameter below DN110 needs to be cooled for more than 20 minutes, and the diameter above DN110 needs to be cooled for more than half an hour. It is also judged according to the feel, if the temperature is not very hot, it proves that the cooling time has been reached. Pairing and fusion interface on the other end are possible. After opening the fixture, remove the fixture to check the appearance of the fusion joint. The height and width of the hot-melt ring should be uniform and beautiful, and its height and width should be appropriate.

The construction and installation of PE water supply pipe should be strictly operated in accordance with the welding operation instructions of the hot-melt butt machine, including the hot-melt time, cooling time, welding temperature, reasonable loss, welding voltage and other welding parameters of the pipe. The welding operation process of the PE pipe is very strict. If it is slightly inadvertent, it will affect the welding quality of the entire project and affect the normal operation of the pipeline.