What are the Advantages of PVC Pipes?
PVC (polyvinyl chloride) is one of the most sought after material in the manufacture of pipes whether for use in plumbing or in industrial application.
And it is not hard to see why PVC pipes are the pipes of choice in plumbing, construction and the manufacturing industries. These pipes have very many advantages over other types of pipes and hence their popularity.
The advantages of PVC pipes over other types of pipes are:
- Lightweight and strong
- Easy installation
- Leak-free joints
- Smooth interiors
- Great insulator
When compared against cast-iron specifically, PVC is lightweight but strong, easy and cheap to install, can last as long as cast-iron and importantly does not corrode. Cast-iron are badly affected by tree roots once they start to age resulting in frequent clogs/backups unlike PVC pipes.
The main disadvantage of PVC pipes is that since they are lightweight, they are more likely to crack when dropped or during earthquakes. Also, not all PVC pipes can be used to transport hot water, and when they burn toxic gases will be emitted.
Benefits of PVC Pipes
Let us now look at the benefits of PVC pipes over other pipes made with different materials like cast-iron, ABS, copper, concrete, etc.
One foot of a 6-inch PVC pipe weighs 5.42 pounds. On the other hand, the same size of a cast-iron pipe weighs 214 pounds. That is very big difference in weight between the 2 pipes.
But how does the weight of plumbing pipe affects its usefulness? The big impact of weight of a pipe is its cost.
To start with, if you are installing or replacing your old sewer pipes with cast-iron pipes, you will need a big crew to carry the heavy pipes or even machines especially to hoist and align the pipes.
On the other hand, a single person can carry one section of a PVC pipe by themselves. This means that you will only have a small crew doing the job and no hoisting machinery, which means low cost of installation.
The lightweight nature of PVC pipes also reduces the likelihood of the workers being injured during the installation process. Needless to say, if a section of a cast-iron pipe drops on your foot, you can very easily lose the foot.
We can therefore agree that PVC pipes are safer to install compared to heavy metal pipes.
Transportation companies will also charge you less to transport PVC pipes compared to metals pipes. Since most of these companies charge according to the weight of the load, you will save good money on transport as well.
You can choose to install either flexible or rigid PVC pipes. In United States, most of the pipes used for plumbing are flexible PVC pipes.
Plasticizers like BPA and phthalates are added to the PVC material to give it flexibility. This means that they pipe can be installed around a curve or even when it is installed in a straight line, it will properly handle external pressures like the effects of earthquakes.
There is of course a debate on the safety of plasticized PVC pipes especially given the effects of BPA on the body. The BPA levels in the pipes are however too low and that is why these pipes are still legal in the United States.
I should however mention that plasticized PVC pipes are banned in Europe and many other countries around the world. If you want to install PVC pipes in those countries you need to go with rigid/unplasticized PVC.
One of the things I really like about PVC pipes is their versatility. There is a pipe for every occasion as I have outlined in this post about the different types of PVC pipes.
In summary, the following are the different types of PVC pipes:
- Plasticized PVC pipes
- Unplasticized PVC pipes
- Chlorinated PVC pipes
- Modified PVC pipes
- Molecularly oriented PVC pipes
- Schedule 40 PVC pipes
- Schedule 80 PVC pipes
- Electrical conduit PVC pipes
As I have mentioned above, plasticized PVC pipes have plasticizers added to them to improve their flexibility. If flexibility is what you seek then these are the pipes for you.
Unplasticized PVC pipes, commonly known as UPVC or rigid PVC pipes contains no plasticizers and are in fact quite rigid. They are not used that much in the United States but in Europe, Africa and Asia they are the pipe of choice.
Chlorinated PVC pipes, also known as CPVC have undergone a chlorination process whereby the chlorine content in the PVC has been increased to around 70% by mass. What is the impact of this chlorination though?
The usual PVC pipes will handle water temperature of a maximum 140 degrees Fahrenheit before softening, while CPVC can handle temperature as high as 200 degrees Fahrenheit. This makes CPVC pipes the best pipes in water distribution since they can carry both cold and hot water.
The high chlorine content also ensures that bacteria cannot grow inside and hence water quality is improved/maintained.
CPVC pipes are available in both nominal size and copper tube size. You can therefore replace/connect them in a house with a copper tubing system.
Molecularly oriented PVC pipes (PVC-O) is an improved version of UPVC derived by reorganizing the amorphous structure of UPVC into a layered structure to achieve a new molecular orientation.
The effect of this molecular orientation is that the new material has a very high impact-resistance. Heavy loads can be moved over these pipes and yet the pipes will not break.
Modified PVC pipes (PVC-M) have an impact modifier added to then to increase their physical properties like impact-resistance and ductility. It is therefore very unlikely for these pipes to crack despite being subjected to great external pressure/loads.
Schedule 40 and 80 PVC pipes have different wall thickness. If you want a pipe with a small thickness (for plumbing) then schedule 40 pipes is the pipe to choose.
Schedule 80 PVC pipes have thick walls and can therefore handle high pressure and hence their use in manufacturing and industrial chemical applications. Check out more on that in this post.
4. Good Insulator
PVC, being plastic is a bad conductor or electricity. In fact, it does not conduct electricity which makes it a good insulator.
In construction, electrical conduit PVC pipes are used in the distribution of electric wires to protect them and to also ensure that current does not leak outside should there be a naked wire.
I must however mention that electrical conduit PVC pipes are not the same as plumbing PVC pipes. Plumbing PVC pipes as I have written in this post are thick and pressure-tested while electrical conduit PVC pipes are thin and not pressure-tested.
Although not always the case, electrical conduit PVC pipes are gray in color while plumbing PVC pipes are white. If you are ever in doubt, ask a plumber or the hardware employees.
The one thing that makes cast-iron pipes not last as long as you would want them to is corrosion. This is especially bad when it happens in your sewer line.
Due to its nature, iron will rust when exposed to air and water, both of which are ever present in and around the pipe.
The first effect of corrosion in metal pipes is leaks. Cast-iron pipe will especially leak raw sewage in your yard. It starts as a slow leak which if not fixed will develop into a major leak.
Another effect of corrosion is tree roots in sewer pipes. Tee roots will naturally grow towards a water source and will force themselves through the tiniest of cracks on the pipe and once inside the pipe a thick network of roots will be formed.
Tree roots inside the pipe will affect drainage, and you will as a result suffer frequent clogs or even sewer backups.
The above problems are however unheard off when you have a PVC drainpipe. PVC does not corrode and will therefore not leak and tree roots will not find a way to grow inside the pipes.
6. Smooth Interiors
The inside walls of PVC pipes are way smoother compared to those of other materials like cast-iron and concrete. But how is that relevant?
A smooth pipe translates to low friction, and that directly affects the flow rate of the fluid inside the pipe. In cases like drain pipes where wastewater drains out with the help of gravity only, you want to have as low friction as possible.
A smooth interior wall also prevents the formation of sludge/scales inside the pipe. That is why cast-iron pipes will constantly need to be cleaned (at a cost) while PVC pipes are almost maintenance-free.
The cost of cast-iron pipe is more than double that of a similar size of a PVC pipe. Other materials are even more expensive. That should tell you how cheaper it is to install PVC pipes compared to cast-iron.
Apart from the initial cost of buying the pipe, transportation cost for PVC pipes is also way low compared to cast-iron. Needless to say, a truck will consume less fuel transporting PVC pipes over metal pipes.
Installation cost for PVC pipes is also low compared to metal pipes. To start with, the installation process is fast hence few hours spent on the job and you will also need a smaller crew hence low labor costs.
PVC pipes can last for a very long term thanks to their resistance to corrosion, chemical degradation, shock and weathering. Some of the first PVC drain lines to be installed are still in operation today.
PVC pipes will on average last for about 50 years but some of the PVC sewer pipes buried in the ground can last for up to 100 years.
On durability, PVC pipes are not a clear winner over other materials since cast-iron pipes can last for as long as 100 years. Probably this is the reason some people still prefer the good old cast-iron drainpipes.
9. PVC is Safe
Perhaps the biggest debate on PVC pipes is how safe or not they are. Most of the fears around PVC pipes’ toxicity are however unfounded and I can categorically state that PVC pipes are as safe as their alternatives.
There have been many studies carried out to determine if PVC pipes are safe compared to other materials and it has actually been concluded that PVC pipes have no adverse effects on the environment compared to the alternatives.
Unlike other plastics, PVC material is made from two materials. The material is half hydrocarbons (fossil fuels) and half a salt. This is the most researched plastic and the reason some folks label it as unrecyclable is because most of the products used from PVC are still in use.
PVC as a material is 100% recyclable.
10. Flame Resistant
Fire/flame-resistance doesn’t mean that a substance will not burn. No! PVC just like other materials like wood will burn when exposed to a flame.
What this means is that PVC pipes and other PVC materials are self-extinguishing. If the source of the flame is withdrawn, the PVC will stop burning.
PVC’s flame resistance is due to its high chlorine content, and that is why it behaves different from other plastic materials. It is hard to ignite a PVC material, they have low heat product and even when they burn they char instead of dropping flaming droplets.
I should however mention that if there is a big fire, PVC will burn and emit toxic fumes. One of those toxic fumes is carbon monoxide.
11. Leak-Free Joints
In cast iron drain pipes, leaks will most likely first appear around the joints. The joints on cast-iron joints are threaded which will leak if not properly tightened or when corrosion starts.
On the other hand, PVC pipes have deep insertions, push-together gasketed or solvent cement joints. There are also fusion joints which provide a fully sealed monolithic connection.
PVC pipes are therefore watertight and unlikely to leak.
And basically those are the main advantages of installing PVC pipes over other materials. I hope you enjoyed reading this post.