aquatherm New Zealand
 

Technical

Welding Technique

What is heat fusion?

heat_fusion123_large_optSimply put, heat fusion combines two parts into one.

When heated, Aquatherm's PP-R thermoplastic material changes to a "melt" state where two pieces can be easily joined together. As the PP-R molecules cool, they bind with each other and turn into one piece, the way they would during extrusion or molding.

The fused material has the same strength as the pipe wall, so there is no path for leaks or blowouts.

The heat fusion process takes just a few seconds to make a connection in smaller diameters and only minutes for larger sizes.

Heat fusion requires a direct-contact heat source for fast, consistent results. There are many different styles of contact heat fusion, including socket fusion, outlet fusion, and butt welding. The heat for fusion can also come from an embedded electrical coil, like the kind used for electrofusion.

However it's done, good heat fusion connections will outlast the piping system, reduce maintenance costs, conserve water, and prevent damage to surrounding building parts. There is no better way to join pipes and fittings together.

Welding connections for plastic pipes

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In the field of plastic welding is a homogenous connection of two smilar materials. Two elements of the same material are connected directly without adding any means of connection.

The following fusion techniques are applied for hot and cold potable water supplies:

  • Heating element socket welding 
  • Electrofusion socket welding
  • Butt welding
  • Heating element socket welding

On heating element socket welding, pipe and fittings are fused overlapping and without application of welding fillers.

The heating element is necessary for heating the outer pipe and inner fitting diameter. The heating element socket welding can be carried out either with a welding machine or with a welding device.

Two pipes are always connected with a fitting like socket, elbow or tee.  Fitting, pipe and heating tool must be coordinated in size by keeping the standard.

Electro socket welding

electrofusion400_optThe electro-fusion fittings, applied for electro socket welding, are equipped with integrated resistance wires, which are current carrying during the fusion process. By this the inner diameter of the socket and the outer diameter of the pipe are heated up to welding temperature resulting in a melting mass on both parts. After their cooling there is an inseparable homogeneous connection. The necessary electrical energy is automatically supplied by suitable electro-fusion devices. Environmental influences are considered by the barcode and temperature compensation of the electro fusion device.

Butt Welding

Chilled Install MacMillans 2_optButt welding is a welding technique used to connect pipes and fittings in dimensions of 160mm OD and greater without the use of sockets as in connections 16mm to 125mm.  Butt-welding is an economical and reliable way of joining 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 ideal for prefabrication, processing long runs and simile to socket fusion does not require additives, grinding and hot works permits.

Aquatherm  offers training and the hire of the equipment needed for this process.

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