Butt-welding is an economical and reliable way of jointing without using additional components. A butt-welding joint is made by gradually heating up the two weld ends with a weld plate and then joining them under a specific pressure. This process is very suitable for prefabrication and producing special fittings.
All Akatherm products can be welded using this jointing method, the fittings can be maximally shortened with the k-dimension (when indicated in the catalogue) and still be butt-welded. Akatherm has a complete range of butt-welding machines available.
Butt-welding is a reliable way of jointing when a proper weld has been made. The butt-weld process consists of the following 6 steps (please refer to our Specification Manual for the complete process and time table). Also available is a machine butt-welding and a manual butt-welding video.
- 6 steps of the butt-welding process
Good preparation consist of making sure the butt-weld machine is clean and works properly. The products that are to be joined using the butt-weld machine need to be cut on a straight angle, properly aligned in the machine and clean as well.
2. Machining the surface
Machining the surface makes sure that both sides run parallel and join up correctly. All shavings should be removed and the weld end remain clean.
3. Preheating under pressure
Press the two ends to be jointed gradually to the heating element until a bead is created. The size of the bead is a good indication that the appropriate pressure and time is used.
4. Heating up with less pressure
HDPE is a good insulator, therefore at this stage it is necessary that the correct heating depth of the pipe ends is obtained. Only a small amount of pressure is required to maintain the contact of the ends with the heating element. The heat will gradually spread through the pipe/fitting end. The size of the bead will increase a little.
5. Change over
Remove the heating element from the jointing areas and immediately join the two ends. Do not push the ends abruptly onto each other. The removal of the heating element needs to be done quickly to prevent the ends from cooling down.
6. Welding and cooling
After the jointing areas have made contact they should be joined with a gradual increase in pressure up.