Top 10 applications of PVC pipes you should know

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Types of pipes used in plumbing

There’s a range of factors to consider when choosing the best type of pipe to use in plumbing and construction. Here’s a breakdown of four common types of plastic and how their properties compare to copper pipes.

Copper pipes

Known for their exceptional durability, resistance to corrosion and a multitude of other benefits, copper plumbing pipes can last for decades and are naturally anti-microbial. Better yet, they are infinitely recyclable and do not lose any of their benefits during the copper recycling process.  

With its ability to withstand extreme temperatures, pressures and exposure to UV and oxygen, copper can be used for a range of purposes and across a multitude of environments, without its integrity being altered.

Polyvinyl chloride (PVC)

PVC is a combination of plastic and vinyl and is a popular choice for mains water lines. However, PVC pipes are not as flexible as some other types of plastic pipes. Additionally, because PVC warps and can melt temperatures of around 60°C, PVC pipes cannot be used for supplying hot water or heating to buildings.

Cross-linked polyethylene (PEX)

Unlike copper, PEX cannot be recycled at all as it doesn’t melt down like other types of plastic. When used for plumbing, PEX pipes can’t be directly connected to a water heater, as they require 18-inches of a heat-resistant material – usually copper – to be connected to the water heater before it is connected further down the line. 

In addition to this, PEX pipes are only suitable for indoor use as they can be damaged by sunlight. It is one of many types of plastic that has been flagged for contamination caused by thermal degradation, and often affects taste and odour of drinking water.

Chlorinated polyvinyl chloride (CPVC)

Common in industrial plumbing, CPVC plastic pipes are PVC pipes which are treated with chlorine. While this makes CPVC pipes better at handling hotter temperatures and pressures than standard PVC, this plastic tends to crack when subject to colder temperatures and will break down when exposed to sunlight for extended periods of time.  

This makes it an unsuitable material to use for plumbing pipes that need to be outside or underground, such as water mains, which is not the case for copper pipes.

Multi-layer plastic pipes

Multi-layer pipes are made using two thin layers of plastic – typically a form of polyethylene (PE) – with a layer of aluminium in between. This material is complex in terms of recycling, as it is virtually impossible to separate both materials, even if the plastic was reusable. Like many plastics, the outer coating can be damaged by UV rays which reduces its use to indoor only.

The advantages of copper vs plastic pipes

From durability and versatility to safety and sustainability, there’s a multitude of reasons to favour copper in the debate between copper vs plastic pipes.

Copper pipes are infinitely recyclable

Copper pipe has a unique ability to be safely recycled over and over without any loss in performance or properties. It’s estimated that around two-thirds of the 550 million tonnes of copper produced since are still in use today. 

Though copper recycling rates vary from country to country, recycled copper already meets more than 30% of global copper demand. In Europe, half of the region’s demand for copper is currently being met with recycled materials, and there is room for recycling rates to grow further. 

Despite industry claims that plastic pipes are fully recyclable and have a circular, end-of-life economy, most plastics are still not being recycled. Only around 9% of global plastic waste is recycled, while 50% ends up in landfill. 

One reason for this is that many plastic pipes aren’t recyclable. For example, multi-layer composite (MLC) tube, consisting of layers of plastic and aluminium, is a prime example of a commonly used plumbing material that cannot be recycled.  

Additionally, plastic compounds such as PVC, PEX and PE all deteriorate over time, making them less and less suitable for recycling. 

According to the University of Wisconsin-Madison, around 100 million tonnes of multilayer thermoplastics are produced globally each year and, because there is no way to separate the polymers, almost all of that plastic ends up in landfill or incinerators. 

Many claim that multilayer plastic pipes are recyclable but, as it stands, there are no recycling frameworks in place, so its ‘recyclability’ is currently nothing but theoretical.