Electrofusion Best Practice
August 23, 2022
Electrofusion is a method of joining PE pipes using fittings with integral heating elements. Socket fittings are used to join mains and service pipes; and saddle fittings are used to connect services to mains.
Prepare the pipe to be joined by removing the outer surface layer to a depth of around 0.2mm, pipe and fitting are then clamped together to prevent movement. A voltage is applied across the fitting terminals via a control box.
An electric current is passed through the wire which heats the wire and melts the polymer, fusing the fitting to the pipe. After welding, allow the joint to cool before removing the restraining clamps.
Ensure that surface water is removed and a groundsheet is used to isolate the jointing area from the trench floor.
electrofusion tip
Check that both pipe(s) and fitting to be joined are compatible, only compatible materials should be joined together.
Check PN and SDR rating marked on fitting and compare with that of the pipe. If in doubt, seek advice from the pipe or fitting manufacturer.
Electrofusion fittings up to 630mm are suitable for jointing in ambient temperatures between -10°C and +40°C. For jointing outside these temperatures, or size range, guidance should be sought from the manufacturer.
Quality Checks
Check for any error messages on the control box.
Check fusion indicators have risen on both sides of the fitting.
Check for signs of melt exudation from the ends of the fitting.
Check that the pipe has not moved by looking at the insertion depth marks.
best practice electrofusion
ELECTROFUSION DO’S
- Use a shelter and ground sheet in both wet or dry conditions.
- Always use equipment that has been regularly maintained and calibrated.
- Ensure control box voltage is compatible with fitting.
- Always use alignment/restraining clamps.
- Cut pipe ends square for electrofusion sockets.
- Scrape pipe and/or spigot surfaces fully.
- Keep scraped pipe and/or spigot surfaces and fittings clean.
- Ensure correct fusion and cooling times are adhered to.
- Assemble joint and fuse immediately after scraping pipe.
- Carry out quality checks before cutting through pipe.
- Mark the fused fitting with the joint number for traceability.
ELECTROFUSION DONT’S
- Do not start the joining process unless it can be completed in one go.
- Do not leave fittings out of protective bags.
- Do not use dirty fittings.
- Do not touch prepared pipe surfaces or fusion areas.
- Do not allow assemblies to get damp prior to joining.
- Do not touch fusion indicators during the welding cycle.
- Do not remove joint from clamps until the full cooling time has elapsed.
- Do not use control box in a trench with gaseous atmosphere.
- Never fuse a fitting for a second time.
- Failed joints should not be used. Cut out failed joint and fuse another fitting to the required specification on distance from failed fitting.
- Electrofusion joints should not be carried out on slotted or drilled pipe sections, only solid walled pipe sections.
Important Note: It is imperative that both the pipe and fitting jointing surfaces are kept clean and dry during the assembly and welding process.
This is best achieved by preparing the pipe and then immediately assembling. Manufacturer-approved isopropyl welding wipes should be used to clean contamination from the joint surfaces.
clean is king
Check that clamps and liners
are correct and clean. Advice on appropriate clamps and scrapers is available from all fitting manufacturers.Check that the scrapers are clean and the blade is not damaged and is in good condition.
Check that the fitting is still in its original packaging and that the bag is not damaged or contains any condensation or dust.
