What Are Cast Iron Pipes?

Cast-iron pipes are typically used to transport both sewage and water. They have been around since before plastic pipes entered the market, which makes them one of the oldest systems we have.

Today, though, a lot of them have been replaced by PVC and other types of plumbing pipes. You might still find some of them which is why you need to know the basics of how these pipes work.

A standard cast-iron pipe works for about 75-100 years and if maintained well, some can last even longer. They are great with pressure systems even though they are susceptible to corrosion. When that happens, you will see rust forming on the pipe. Despite this, they are still a good choice for homes. However, they are being replaced because there are cheaper options available.

Here’s what you need to know about them if you want to install cast-iron pipes for your home.

Advantages of Cast-Iron Pipes

  • Cast-iron pipes last a long time and have thick walls.
  • You will notice that CI pipes installed in the last century are still in decent working condition which means you don’t have to worry all that much about damage.
  • Even when parts of the pipe are damaged, they can be replaced and used.
  • This is a durable material that is good when there is high or low pressure in the system and it is very hard to destroy them. They are also heat resistant.
  • These pipes make very little noise because they can handle the vibrations in between fittings.
  • Cast-iron pipes come in different sizes with the smallest usually being four inches.
  • The corrosion rate is just the same as steel and iron which is good news and the walls are thicker than steel and iron.
  • Their abrasion resistance is impressively high which makes them a great choice for dishwasher and garbage disposal water systems.
  • When you use chemicals, you can rest assured that cast-iron pipes will not react to them and hence neither melt nor burn.
  • Installation is quite easy because there are many ways of joining the fittings for cast-iron pipes. They are also cheaper than other materials and relatively easier to use.
  • They have excellent water-sealing capabilities and can handle extreme movements in case of an earthquake.

Possible Problems with Cast Iron Pipes

While they have a lot of admirable qualities, cast iron pipes are not without flaws. That is just one of the reasons, a lot of households have now moved on to other materials.

  • Corrosion is unavoidable with cast iron pipes. This makes them weak and might even cause them to collapse which gives way to other major plumbing problems.
  • Rust is another eventuality when the pipe and sewage water come into contact regularly. And it reduces the pipe’s hydraulic capacity and flow velocity on the surface.
  • Wastewater might escape from the pipe because it can create a channel on the pipe’s bottom over time. You need to inspect this regularly.

Are PVC Pipes Better than Cast-Iron Pipes?

Despite their strength and durability, cast-iron pipes are being replaced with PVC pipes. Here’s how they fare in comparison.

  1. Cast-iron pipes will definitely last a lot longer than PVC pipes. The lifespan of the latter depends on the temperature limits. But CI pipes get corroded and rusty which PVC pipes don’t.
  1. With PVC pipes, you need to think about where you are using them and the temperature and acidity of the water or sewage that will flow through them. That is not a concern with cast-iron pipes.
  1. If you are going to use PVC pipes near hot regions, you need to seal them at the penetration because these pipes are not fire-proof.
  1. On the other hand, installing PVC pipes is a lot cheaper than cast-iron pipes. Cast iron is easy to handle but PVC is easier which is why contractors like it.
  1. Cast iron pipes are great in terms of reducing noise but PVC pipes are not. This is because their walls are a lot less dense than CI pipes. So when your wastewater is getting out of the way, expect a lot of noise if you have installed PVC pipes.

The Bottom Line

A lot of people who built homes back in the 70s used cast-iron pipes because they liked their performance, lifespan, and durability. But today, your requirements might not be the same. But remember that it is still a pretty good choice.

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