Why would you choose Poly Pipe over PVC?

26 August 2020

Poly PipeTraining

When it comes to pipe, not all materials are created equal. At Advanced Piping Systems, we stock Poly Pipe products because we know they are the most versatile, durable and sustainable products on the market.

But what are some of the other types of pipe used? How do they differ from Poly Pipe, and what are the benefits and disadvantages of these other piping materials?

 

Comparing PVC with PE

One of the most common piping materials is polymerizing vinyl chloride, commonly known as PVC.

PVC is a product derived from vinyl, as its name suggests, and is made through a process of thermosetting plastic. 

Standard PVC is not resistant to UV at all, which means that the sun can burn PVC pipes, turning them brown and yellow, and making them brittle. This UV damage can often lead to cracking and leaking, which makes it less than ideal as a long-term industrial solution.

PVC also has limited chemical resistance.

In comparison, Poly Pipe (also known as PE) is derived from the base material HDPE, which has good chemical resistance, is UV stable, and is resistant to cracking, impact and abrasion – this is because it’s made from an elastic material which allows it to flex naturally. 

Although Poly Pipe can often take longer to install (as it must be fused or electrofused with buttwelding or EF welding eqiupment), it is a permanent solution, proven to last for over 100 years. 

Because of this, Poly Pipe is the preferred solution on mining sites, as it’s an industrial strength pipe that maintenance teams, processing plants, and engineers can rely on long-term.

You’re only really likely to see PVC on mining site camps in semi-permanent, above-ground structures – such as drains and ablution areas – which sometimes use PVC as a short-term solution.

 

Comparing concrete pipes with Poly Pipe

Another material often used for large industrial piping projects is concrete.

Poly Pipe is a much lighter weight product than concrete or concrete lined steel pipes, which makes it easier to transport, maneuver and install.

Concrete lined steel pipes and PVC pipes also cause major problems when being fitted, as they are more difficult to join – relying on rubber seals or glues to fill gaps, which often leads to pipes sliding out of place or loosening, causing cracks, slips, breaks and splits in pipelines.

That’s why in the piping industry, we often tell people that if you can’t fuse it, you’ll lose it…or fuse it, don’t glue it!

Another downside of concrete pipe is that it can change the PH of water, because of the chemicals in the concrete. Because of this, concrete pipes may require recoating of the internal pipe service over time as it pits and breaks down.

Fully welded systems, which are only viable using Poly Pipe, don’t require thrust blocks or glues to stop pipes coming apart at rubber ring joints, circumventing these issues.

Poly Pipe can also be directionally (or horizontally) bored into the ground, providing a no-dig solution that can not be replicated in the installation of other materials.

 

When might you use PVC instead of Poly Pipe?

When it comes to PVC it’s important to think about the size and longevity of the project.

Smaller jobs that only require a short-term solution, such as above ground plumbing or low impact irrigation systems using pipe under 50mm PVC is fine.

Some skid mounted water treatment systems use PVC in sizes under 90mm. This may be ok if the pipe is housed inside a pump or filter shed, however, it won’t have the elasticity Poly Pipe provides, and as such, it may hammer with changes of pressure. We know that extreme pressure changes can crack PVC pipe elbows or threads under these circumstances.

The only other circumstance where you may choose to use PVC over Poly Pipe is in the case of using rubber ring jointed 100mm and 150mm pipes for water mains.

PVC works well in these cases as rubber ring joints are very quick to push together and don’t need any additional equipment, which makes them easy to install and hard to beat on price. Having said that, for long term use PVC is certainly not fail-safe, particularly in unstable soils.

It’s also important to remember that PVC is not common trench friendly (where many pipes and conduits run next to each other within a trench), so it’s often not the best solution for piping in camp areas, or short-term irrigation for this reason.

With all of this in mind, the initial savings made by using PVC are often overridden by the need to reinstall it more regularly than Poly Pipe.