Electrofusion welding is among the new polyethylene joint welding methods which will be elaborately discussed in the present article.
Polyethylene connection methods:
As you know, there are four ways to connect polyethylene joints in various projects such as water supply, irrigation, facilities, gas, oil, and petrochemicals. These methods include:
1.Threaded joints
2.Electrofusion welding
3.Butt fusion welding
4.Flanged
The present article will discuss electrofusion welding and butt fusion, and compare their benefits and advantages.
Polyethylene electrofusion joints:
These types of joints were the first to be used in the country and are currently the only connection method approved by the National Iranian Gas Company that entered the country’s facilities and water industries over time due to their high reliability.
The reason for the increased share of electrofusion joints in facilities and water industries is their positive performance in various projects, their qualitative advantages over butt fusion welding, etc. some of which will be mentioned as follows.
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No human interference in the quality of electrofusion welding:
The lack of human interference in electrofusion welding quality is among the advantages of polyethylene electrofusion welding compared to but fusion. Butt fusion lacks this advantage.
The procedure is that the welding operator transfers all electrofusion joint data including size, welding time required, type of connection, electrofusion connection company, etc. to the machine after preparing the connection and the pipe, placing the joint between the pipe, or connecting the two sockets of the joint welding device to the electrofusion joint pin, and reading the connection barcode by the barcode reader of the electrofusion welding machine, and the electrofusion welding process starts automatically after pressing the Start button.
At the end of the welding operations, the welding machine beeps to notify the operator that the procedure has ended, and the electrofusion welding finishes after the joint socket is disconnected.
As can be inferred from the descriptions of this type of welding, the welding process has no impact on the quality of electrofusion welding while many factors such as the time of removing the iron, cooling time, etc. are influenced by the operator in the case of butt fusion welding.
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Electrofusion welding speed
Higher welding speed or shorter welding time is another advantage of electrofusion welding over butt fusion welding in polyethylene joints which plays a significant part in the speed of project execution.
For instance, comparing the welding time of butt fusion and electrofusion speeds at the size of 63mm indicates that butt fusion requires around 20-25 minutes according to international standards such as DVS2207 and INSO18648, while this time drops to 3-7 minutes in the case of electrofusion joints with preparation and welding time included which indicates the higher speed of electrofusion joint welding.
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The ability to connect to two different pressures or SDRs
Considering that the junction is at the edges of the two parts in butt fusion welding, having the same thickness at the two sides of the part is significantly important and necessary (per the DVS2207 standard), while electrofusion welding is performed on the exterior surface of the part and there is no need for the two sides to have the same thickness or SDR.
It can be concluded from these explanations that the possibility to weld two parts with various SDRs is another advantage of electrofusion over butt fusion.
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No need for various welding machines
Welding a wide range of sizes by one machine is another advantage of electrofusion welding. Butt fusion devices are manufactures in specific size ranges. For instance, butt fusion welding machines are generally manufactured in the size ranges of (63-160), (355-200), and (640-400).
The operator needs multiple machines to carry out but fusion in various sizes while the electrofusion welding machines such as the German Horner machine whole exclusive representative in Iran is Takab Etesal Damavand, can carry out welding in sixes 20-200 using only one machine.
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No need for a quality supervisor
The fact that electrofusion welding does not need a quality supervisor on the project site is another one of its advantages. This advantage originates from the fact that some polyethylene electrofusion welding machines can save electrofusion welding information such as the time, size, the type of joint, and sometimes even the welding location as PDF files which eliminates the need for the physical presence of a welding quality supervisor at the project site since electrofusion welding quality can be examined based on the data saved on the device.
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Larger reliance surface in electrofusion compared to butt fusion welding
It is noteworthy that the welding surface in electrofusion welding is greater than in butt fusion which increases the reliability of electrofusion welding and joints.
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Lower costs
The lower costs of project execution can be mentioned as the last advantage of electrofusion joints which has unfortunately been misunderstood by many technicians.
Many assume that electrofusion joints cost greater, but taking a glance at the advantages mentioned in this article makes it clear that electrofusion joints cost less than butt fusion if all parameters such as project execution time, the number of welding machines needed at the project site, etc. are taken into account.
Studies conducted by Takab Ettesal Company using value engineering have concluded that electrofusion joints have a lower final cost compared to butt fusion joints in sizes up to 250. Besides, the use of electrofusion joints in sizes over 250 is also justifiable due to their higher durability over the operation period. We hope for a day when we will be able to say confidently that water supply, installation, and other projects in our dear country, Iran, are being completely carried out using electrofusion joints as in large European countries.
