Electrofusion Welding Technique

Electrofusion welding of polyethylene pipes should be done in accordance with the international standard such as DVS 2207.

In the electrofusion welding method, the welding is done with the heating resistors in the sleeve part. After the pipes are placed in the sleeve, the ends of the welding machine are connected to the resistance ends of the sleeve in the hole, and the resistances are heated with current. As the wall thickness of the sleeve is greater than the wall thickness of the pipe as a result of the heating of the resistances, the temperature of the tube wall becomes higher than the temperature of the sleeve wall. Due to this temperature difference, pressure builds up inside the pipe. Thanks to the pressure on the pipe and the pressure created in the pipe, the welding process takes place.

Electrofusion welding machines used for this welding process are not only light, they also allow welding with variable welding parameters and obtaining information documents of the welds if necessary..

• Pipes made from the same raw material can be welded in the electrofusion welding process.
• Melt flow rate for HDPE-electrofusion bonding is 0.3....1.7 gr/10 min. (It is l90°C/5 kgj. The melt flow rates of the pipes to be welded and the sleeve must be between these values. Pipes with the same melt flow rate can be welded.
• The area to be welded must be protected so that it is not affected by bad weather conditions. (For example: Snow, rain, wind, effective sun rays, etc.)
• The temperature of the environment to be welded should be between 5°C and 50°C.
• In general, there are barcode readers on electrofusion welding machines and barcodes that contain welding parameters on electrofusion attachments. While the welding parameters are loaded to the machine via the barcode, the welding parameters written on the attachment can be manually loaded into the welding machine and welding can be performed.

Welding parameters

There is a barcode reader pen on the latest technology welding machines. The welding parameters of the EF insert to be welded are attached on the barcode or on the sleeve or in the package. pressure test

Pressure test

There is a barcode reader pen on the latest technology welding machines. The welding parameters of the EF insert to be welded are attached on the barcode or on the sleeve or in the package. pressure test

The pressure test should be started at least one hour after the end of the welding process, after the pipes have completely cooled down.

EF Welding Procedure

1 - The ends of the pipes to be welded are cut straight and smooth, and the entrance limit is marked on the pipe by placing them inside the fitting to be welded up to the abutment limit.

2 - The surface of the pipe to be welded should be cleaned and surface oxidation should be taken with scraper before welding.

3 - Attachments to be welded should be removed from their packaging at the welding stage, electrofusion surfaces to be welded should be cleaned with industrial alcohol, and the welding surfaces of the pipe and attachment should be protected from hand contact after cleaning.

4 - Afterwards, the fitting to be welded is placed on the marked part of the pipe up to the resistance limit of the fitting.

5 - It is fixed after checking the electrofusion welding ends as straight with the pipe, with the ends facing upwards. Welding machine sockets are placed on the welding ends of the fitting and made ready for welding.

6 - After the machine gives the ready signal for the welding process, the welding process is started by reading the barcode or by entering the manual welding parameters. In general, welding machines show the welding time and voltage on the screen and automatically terminate the welding process and give an end signal.