In the plumbing game not all pipes align or match in size!


Got two pieces of pipe you need to join and they aren’t the same diameter?  PLASSON compression reducer fittings can easily join two lengths of different-size metric HDPE pipe. Reducing sets also help you modify PLASSON fittings to connect pipe of different sizes.

Compression reducer fittings match common pipe sizes and are usually PN16 rated.

‍Compression reducers are suitable for water and other similar fluids with pressures up to 16 bar, however, this varies with the ambient temperature and temperature of the pipe contents.

A compression reducing tee fitting is used to tee off a metric HDPE pipe and add a smaller size outlet. Compression reducing tees are often used to supply water or other fluids off a main pipeline because the smaller off-take provides less flow than the original pipeline.

PLASSON reducing sets are available in the 110mm to 20mm range. They can be inserted into will existing PLASSON metric compression fittings to reduce the size of the outlet whilst maintaining pressure ratings and eliminating leak risk.

Increase flexibility of existing fittings – convert tees or elbows to another size

Reduction without threads – eliminate leak risk and maintain pressure rating

Utilises the Plasson Captive O-Ring system – no movement and high compression

Poly to Copper adaptor kits available

Compression reducers are suitable for outdoor use and are resistant to etching by numerous chemical substances and are UV stabllised.

These fittings are compatible with PELD, PEHD, PE40, PE80 and PE100 pipes, and may also be known as compression reducing joiners, compression reducing couplings, compression reducing couplers or compression reducing pipe joiners.

Click here to see how easy reducing sets are to install


Install PLASSON 1/2” – 2” Rural Fittings in four easy steps:

Ensure the surface of the pipe being inserted is free of scratches and other imperfections

Ensure both the end of the pipe and the fitting itself are clean of sand, mud, stones, etc

Do not over tighten the nut – this can spread the nut cone and result in pull outs

When fittings are reused it is crucial to replace the grip ring to avoid pipe blow outs.

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PLASSON’S Universal Slip Repair Coupling can repair a variety of different pipes, sizes, or can join together two separate pipe materials. The pipe is quick and easy to fit and it can freely slide back and forth before being tightened in the desired position. The repair coupling provides a watertight seal within the system, with the seal compression increasing as the pressure increases.

This impressive design is built to last 50 years, providing high impact strength and stress resistance.

  • Suits a variety of plastic and metal pipe materials
  • Each fitting designed to fit a wide range of diameters
  • Zero force pipe insertion – can slide freely back and forth
  • Thick o-ring seal – compensates for poor pipe quality
  • Seal compression increases as pressure increases
  • Robust PP body and nut – high impact strength and stress resistance
  • Long sealing area – can bridge over damaged section or gap between pipes
  • Total reliability – PN16, designed to last 50 years Suitable for all cold water applications up to 45º


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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

Wondering how to join pieces of pipe of different sizes?   PLASSON make it simple.  Reducing sets and reducing fittings are the quick and reliable way to connect different diameter HDPE pipe.

Compression reducer fittings match common pipe sizes and are usually PN16 rated. Reducer compression fittings are made from PE100 and are precision molded to they are light yet tough.

Using a compression reducing tee off a metric HDPE pipe provides a smaller size outlet to the main pipe
Compression reducing tees are often used to supply water or other fluids from a main pipeline
The smaller off-take will have less flow than the original pipeline

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Push-fit fittings are popular in Australia because they provide an easy and secure connection with a simple, well, push. Popularly used throughout plumbing, quick-connect fittings can be found anywhere that requires the transporting of water.

PLASSON has a range of PushFit fittings called Series One.

Series One Push-Fit couplers provide connect PE to a variety of plumbing pipe materials including PEX.

Inserting the pipe up to the fitting stop creates both the seal and grip on the pipe – ensuring a full seal in positive and negative pressures.


How good are PLASSON PushFit couplers?  They are a tough, secure option for connecting PE and other pipe materials such as copper, PB, PEX.  Series One fittings are compact and minimal so are ideal for residential plumbing, where space can be limited and appearance is crucial.
PLASSON Series One fittings are available exclusively in Australia through Reece.
The range includes elbows, tees and adapters as well as a range of standard couplers for PE pipe sizes 20mm, 25mm, 32mm, 40mm and 50mm .

Poly pipe joiners are easy to use and learning how to install leak-free poly pipe joiners is also easy too:

Incorrect installation
When pushing fittings onto the pipe, ensure the pipe is inserted fully. If the fitting is only partially inserted onto the pipe it will not create a watertight seal. When the pipe is traveling through the fitting there will be some resistance. This means you can think the pipe has been pushed all the way into the fitting.   Making a witness mark will help show how far the pipe needs to be inserted in order to reach half way into the fitting.

Pipe issues

In order to seal tightly inside the fitting, pipe ends need a clean, straight cut. If the end is jagged or uneven, it will not create a watertight seal

If the tubing is cut on an angle, it is unlikely to seal and could also nick the O-ring

One way to avoid these issues is to cut pipe with a pipe cutter rather than a blade or saw

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PLASSON Metric Compression fittings are one of the most reliable ways of connecting poly pipe.  The are engineered to deliver long-lasting PE pipe joins for residential, civil and commercial water and waste water pipelines.

PLASSON Metric Compression fittings have been connecting Australian poly pipelines for over 40 years.

Watch how to install metric compression fittings or follow the four steps below: