Water

Water use, sustainability, and efficiency by choosing quality systems and materials, and providing environmentally friendly solutions.

Pipe jointing systems

The type of pipe jointing system used depends on the pipe material.

Jointing system

Copper

PB

PP

uPVC

PE

PEX

Brazing

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Manipulative mechanical jointing

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Non-manipulative jointing

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Crimp ring

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Sliding sleeve

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Heat fusion welding

 

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Solvent cement welding

 

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Brazing is the most common method for joining copper pipe in New Zealand. Straight joins are made by soldering using a solder that comprises copper, phosphorus and 15% silver, to create a lapped capillary joint that is permanent and durable.

Manipulative mechanical jointing uses brass fittings to make copper pipe connections. A nut is placed over the end of the pipe and a swaging (crox) tool is inserted to expand the pipe, creating a rolled groove to secure the nut in position. The joined ends are made watertight using plumbers’ hemp or thread tape. This joint is most commonly used for connecting pipes to valves and fixtures. It is prone to loosening over time and should therefore not be used in concealed or inaccessible locations.

Non-manipulative jointing also uses brass fittings, but instead of expanding the pipe with a swaging tool, a brass ‘olive’ is placed over the pipe and compressed between the nut and fitting to create a secure joint that can easily be separated later.

Crimp ring uses an external stainless steel or copper ring that is placed over the pipe, then compressed with a hand tool. As long as the ring is correctly placed and aligned, the resulting joint is very robust.

Sliding sleeve uses a sleeve that is placed over the pipe end and then expanded to go over the serrated spigot. A special tool forces the sleeve over the pipe and spigot to create an effective joint. Sleeves can be removed with the application of heat and then reused. The disadvantage of this connection is that the tools to create it can be difficult to use in confined spaces.

Heat fusion welding is where the surface of the pipe and connection are melted together using a heating iron. As the two ends are overlapped and fused without the application of welding fillers, the result is effectively a continuous pipe.

Solvent cement welding also overlaps and fuses the pipes but uses a solvent to ‘glue’ the pipes together.