THE POLY PIPE ABC’S: PN TO SDR

Why does poly pipe have a coloured stripe?  

And what about the markings on PE pipe….

The external stripes on polyethylene stripe indicates the type of medium it contains:

blue stripe = mains water

red = fire mains

purple = recycled water

yellow = gas

green = agricultural

Polyethylene, or PE, pipe has been successfully used throughout the world for more than 50 years. The main benefits of PE pipes and fittings are corrosion resistance, high strength, toughness and flexibility, so it’s no wonder it is a popular choice of water worldwide.

Aside from the colour indicating what is being carried by the pipe, there is valuable detail printed on the pipe too.

What is PN?

PN is printed on the pipe and, in the case of blue line pipe this is PN16. The acronym PN stands for Pressure nominal.  When a pipe has a rating of PN16, it is designed to handle 16 Bar internal pressure. This pipe can also be used to carry compressed air.

Metric Poly Pipe comes in different diameters, with popular sizes being 63mm and 25 mm, and in different pressure ratings:

PN10 which has a maximum pressure rating of 1000kpa
PN12.5 which is for a maximum of 1250kpa
PN16 for a maximum of 1600kpa

What is OD?

The OD is also printed on the pipe.  This is the Outside Diameter, or OD, of the pipe measured in ‘mm’.

The there is also the acronym SDR, which stands for Standard Dimension Ratio. When the outside diameter of the pipe is divided by the SDR, it gives the thickness of the pipe wall.

These are all important measurements to know and understand when installing pipes that will carry fluid under pressure.

What is PE100?

Pipe that carries potable water in Australia is made from PE100 which is a type of plastic resin that has been proven to have a minimum required strength (MSR) of 100 at 50 years and 20 degrees celcius.  But the operational service life of PE pipelines is dependent upon a number of factors that include: raw material quality, processing conditions, installation, the aggressiveness of the fluid transported, operating pressure and temperature.

‍Click to watch how OD, SDR and PN work together

0 replies

Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply

Your email address will not be published. Required fields are marked *