A vital piece of kit when it comes to plastic piping systems is a pipe stiffener (also known as pipe liners or pipe inserts).
All of our push-fit plumbing fittings ranges, PolyPlumb, PolyFit and PolyMax, require a pipe stiffener to be inserted into our plastic pipe prior to jointing. This counteracts any loss of shape which may have occurred whilst cutting the pipe and makes for a secure seal between the pipe and fitting.
We offer 3 different types of pipe stiffeners dependent on fitting type or installer preference:
Plastic Pipe Stiffeners
Plastic pipe stiffeners can be used with all push-fit ranges – PolyPlumb, PolyFit and PolyMax.
Sealed Pipe Stiffeners
Sealed pipe stiffeners, which provide enhanced sealing can be used with PolyFit and PolyMax only.
Stainless Steel Pipe Stiffeners
Stainless steel pipe stiffeners can also be used with all push-fit ranges – PolyPlumb, PolyFit and PolyMax.
Sealed Pipe Stiffeners
The Polypipe sealed pipe stiffeners have been designed to provide enhanced sealing and can be used with PolyFit and PolyMax fittings. The sealed stiffener (highlighted in green in the image above) incorporates two rubber ‘O’ rings to give additional security. The seals are positioned at the head of the stiffener and on the outside of the spigot to seal on the pipe bore.
Polypipe sealed stiffeners are supplied pre-lubricated. If any further lubrication is required then only Polypipe silicone lubricant should be used - substances such as solder flux must not be used.
To aid the insertion of the sealed stiffener into the pipe, the pipe should be internally chamfered. The chamfer provides an internal lead on the pipe so the square edge of the pipe does not damage the ‘O’ ring seal. Polypipe offer specific chamfering tools for this purpose. The chamfering tools are available as either individual tools or as a block of four, dependent on installer preference.
Use with Copper, Compression and Press-fit PolySure
When using PolyPlumb, PolyFit or PolyMax fittings with copper pipe, pipe stiffeners are not required. When using our plastic pipe with compression type fittings, only plastic and stainless steel pipe stiffeners can be used. If using our PolySure fittings, the pipe stiffener function is provided within the body of the fitting and is therefore integral – stiffeners are consequently not required.
You can find out more about any of the above in our Plumbing and Heating installation guide here.