Polyethylene (PE) vs Polypropylene (PP) – Pipe Differences

In the compressed air and pipe systems industry, there is a long list of options. From the equipment designed for industry use to the press fittings that connect everything together, engineers and system builders have the luxury of choice. This is due, in no small part, to the ability of manufacturers in the industry to innovate.

Here, we look at two easy-to-confuse piping types. Just one letter distinguishes PP and PE pipes, but they have several unique characteristics that specifiers must familiarise themselves with. Here, we explain why you should choose one over the other

PP (Polypropylene)

polyethylene pipe

The physical attributes of PP are like PE (polyethylene). However, PP becomes more brittle at lower temperatures and it has poorer resistance to compressor oils than PE.  Nonetheless, polypropylene has one of the highest chemical resistance ratings in the plastics category. Here at Air Energy, we suggest that PP should be used for hot and cold liquids, dairy products and laboratory and reverse osmosis systems.

PP can be used to replace existing pipe systems. Unlike steel piping, PP pipes are resistant to corrosion. At Air Energy, we provide two main kinds of PP piping: the standard neutral pipes and the fibre-reinforced green pipes. A complete selection of polypropylene pipe fittings is also available.

PE (Polyethylene)


MaXair® Compressed Air Pipe systems offer pipes rated at PE100. This means they offer 50 years of reliability when used at 30-degrees Celsius. Air Energy was the pioneer in distributing the highly successful maXair® piping systems. This brand currently exceeds most Australian standards in terms of safety and reliability.

Pipes are crucial for any compressed-air or liquid-movement systems. Choosing the right material is important for long-lasting infrastructure that gets the job done and minimises waste. Get in touch with Air Energy and open a gateway to the most reliable products available on the market today. 

What is Poly Tubing?

Poly tubing is a highly flexible, lightweight, and durable tubing made from polyethylene, polypropylene, and polyurethane, which are polymers formed by the polymerisation of ethylene. It is a highly versatile tubing with break and crack-resistant walls. High-density polyethylene (HDPE) and low-density polyethylene (LDPE) are the two most common types of poly tubes (LDPE).

Advantages of Polyethylene

  • Polyethylene has numerous valuable properties that make it suitable for various applications. It has low hardness but is very ductile and impact resistant; it will stretch rather than break. If it was to fail it would only fail in a ductile manner.
  • Polyethylene is water-resistant and durable, so it outlasts other polymers when exposed to the elements.
  • Polyethylene is an excellent electric insulator, providing resistance to electric current but can become electrostatically charged. This can be avoided by using antistatic agents.
  • The transparency of polyethylene can range from nearly transparent to opaque. Low-density polyethylene (PE) is suitable for packaging due to its clarity.

Advantages of Polypropylene

  • It is a reasonably priced material.
  • Because of its semi-crystalline nature, it has high flexural strength.
  • The coefficient of friction is low. It is chemically resistant to a wide range of bases and acids.
  • It has a high fatigue resistance.

Which Should You Use?

There are many similarities between polyethylene and polypropylene. Still, they also have unique properties that can be maximised depending on how they are made and the applications they are used for.


Polyethylene has a good resistance to compressor oils which are present in compressed air to a greater or lesser extent.

Polypropylene has a pronounced lower life expectancy in the presence of oils so for this reason polypropylene is to be avoided and polyethylene is the superior product.