What is Electrofusion Welding?
Electrofusion welding stands as a pivotal innovation in the realm of modern manufacturing. It offers meticulous methods of joining poly pipes and fittings into seamless unions. But what exactly is electrofusion welding?
This blog will delve into the intricacies of the electrofusion welding procedure, discussing its mechanics, advantages, and applications. Read on to learn everything you need to know about this specialised process.
Understanding Electrofusion Welding
Electrofusion welding is a technique for joining thermoplastic pipes together using a moulded socket fitting containing an electrical resistive heating coil and an electrofusion welding machine. An electric current is passed through the coil, generating heat that causes the thermoplastic material at the joints to melt. Once sufficiently melted, the current is halted, allowing the plastic to cool and solidify into a seamless, durable joint.
Electrofusion welding is a pivotal technique in poly manufacturing due to its efficacy, precision, consistency, and reliability. It’s an essential welding method used for industries that rely on strong poly pipeline systems, such as water supply, agriculture, mining, and more. The manufactured fittings are very reliable, but it needs to be emphasized that the preparation and jointing process must be followed meticulously if you are to avoid joint failures, and training is essential as is QA to ensure each step is followed.
The Electrofusion Process
The electrofusion welding procedure involves several steps to ensure a successful and reliable result.
Step 1: Material Preparation
Before starting the electrofusion welding process, thorough preparation of material is essential.
● Thoroughly clean the ends of the pipes and fittings to remove any dirt, grease, and contaminants.
● Square the pipe ends.
● Peel the pipe ends back to virgin material eliminating oxidized material.
● Ensure the surfaces are smooth and free of any irregularities that could affect the fusion process.
● Clean the pipe surfaces with Isopropyl alcohol and lint free cloth.
Step 2: Fitting Connection
The second step involves connecting the fitting to the pipe ends.
● Remove the electrofusion fitting from its protective bag and insert between the pipes to be joined. The fitting contains embedded resistance wires or coils.
● Accurately align and position the pipes within the coupling ensuring straight connections.
Step 3: Clamping
Securely clamp the pipe end and fitting into the electrofusion welding machine by following these steps:
● Place the clamping tool around the pipes and fitting
● Tighten the clamps to secure the pipes and fitting in place. This prevents movement during the welding process.
Step 4: Alignment Check
Checking proper alignment is essential before starting the fusion process:
● Verify that the pipes and fitting are correctly aligned. Misalignment can lead to weak or faulty and leaking joints.
● Ensure that the pipes are centred within the fitting and that any alignment indicators match those on the pipes where necessary.
Step 5: Heating and Fusion
Here’s how you properly conduct the heating and fusion process:
● Start the electrofusion welding machine, which sends a controlled electrical current through the embedded wires in the fitting.
● The current generates heat, causing the thermoplastic material of the pipes within, and the fitting to melt.
Step 6: Cooling Finishing
Proper cooling and finishing techniques are essential to enhance the strength and integrity of the electrofusion weld:
● After the material is sufficiently melted, at the correct time, the electrofusion welding machine will turn off the current. Without moving anything, let the joint cool down and completely solidify. The Cooling time varies depending on pipe size, material time, and ambient temperature.
● Inspect the joint for irregularities, voids, or signs of melt out or inadequate fusion, and check to see the pressure indicators on the fitting have both risen.
● Protect the joint from any potential damage or disturbance. This includes handling the pipes carefully and avoiding external stressors.
Advantages and Disadvantages of Electrofusion Welding
Advantages of Electrofusion Welding
● Electrofusion welding creates strong and durable joints with mechanical properties comparable to the original pipe material.
● Electrofusion welding produces joints that are highly resistant to leaks.
● Electrofusion welding maintains the inherent corrosion resistance of PE materials without needing additional materials.
● Electrofusion welding is suitable for various PE pipe sizes, types, and applications, making it adaptable to different industries.
● The electrofusion welding process is relatively quick and straightforward compared to other welding methods, minimising installation time and labour costs.
Disadvantages of Electrofusion Welding
● Proper specialised training and supervision is essential to ensure accurate control of the welding parameters.
● The initial investment in welding equipment and tooling can be expensive, especially for high-quality.
● Electrofusion welding requires an electric power source, which might not be readily available in all situations.
● Fusion can be affected by ambient temperature, requiring adjustments in extreme conditions.
Frequently Asked Questions (FAQ)
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Electrofusion Welding is mainly used for joining polyethylene (PE) pipes and fittings in industries like poly manufacturing, water supply, and gas distribution.
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The process involves precisely controlled heating and cooling phases, which create a fusion between the pipe and fitting, resulting in a solid, leak-resistant joint.
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While Electrofusion Welding is primarily designed for PE pipes, it may also be suitable for certain other thermoplastic pipes with similar properties, providing fittings are available in those materials.