If you’re experiencing leaking joints and failed welds you need to consider making improvements to all stages of the welding process, as common issues arise from contamination and the use of incorrect tools.
There are many reasons why the wrong tools can attribute to failed welds, including the tools being too bulky, too small, or not covering the size range of the pipe being installed. All tooling used should be fit-for-purpose and capable of doing its job time and time again.
There are two main stages in the EF welding process that, if done correctly using the right tools, can reduce the risk of leaking joints and failed welds.
1. Pipe preparation
This important step provides the foundation for a good weld joint and begins with making sure the HDPE pipe is cleaned and round. If ovality is found, a re-rounding tool/re-forming tool should be used.
Once the roundness of the pipe has been established, the pipes surface oxide layer needs to be removed. Various mechanical scraping tools are available that can remove the surface layer easily as they achieve a consistent peel depth.
Most mechanical scrapers are designed to be used on a range of pipe sizes regardless of the standard dimension ratio (SDR) rating. Using a mechanical scraper ensures that the whole surface, including underneath, has been peeled. Underneath the pipe is the most difficult to scrape using a hand scraper and is often the area where inconsistent or missed scraping occurs.
2. Pipe clamping and positioning
The use of pipe clamps is necessary for all joints. As the fusion process takes place the plastic becomes molten between the fitting and the pipe. This effect creates pressure between the pipe and the fitting, which forces the two pieces to move.
When clamps are used the movement is restricted and the molten plastic is forced together fusing the fitting and pipe. There are various types and styles of clamps for all situations encountered onsite.
Popular clamps have been designed to be used on range of pipe sizes and can adapt to angled joints of between 45° and 90°. Some clamps are designed to offer re-rounding capabilities, which removes the need for a separate re-rounding tool.
These clamps change pipe sizes by inserting or removing liners or shells. Other clamps are designed to be quickly installed and are usually smaller in physical size and don’t offer any re-rounding capabilities.
Whichever clamps are used, they must be left connected to the pipe for the full duration of the cool down time. This is a fundamental step in achieving a leak-free joint as the fused plastic is given sufficient time reform as a solid. This step is often overlooked, clamps are removed too early and the pipe is moved, causing stress on the joint and increasing the risk of leaks.
3. Welding process
The final step in the fusion process is the welding itself, which Caldervale Technology has made easier thanks to welders that have been designed with the operator in mind.
Caldervale Technology’s welders are easy to use, reliable and have a long service life, provided they are calibrated and serviced every 12 months to ensure the voltage produced is stable for the fittings.
Caldervale Technology welding units also feature comprehensive weld data that can be downloaded directly from the welder. Caldersafe data viewer software can then be used to view or print these records which are distributed to all project personnel.
This partner content is brought to you by Caldertech Australia. For more information, visit www.pipefuse.com.au.
