When building a home, you will usually be told by your engineer, plumber, or construction expert about the type of PVC materials to be used.
But, what really are these PVC pipes, specifically schedule 40 and schedule 80 PVCs? Is any of these better?
In this article, we will discuss the difference between these two, their advantages, and their disadvantages.
What is a Schedule 40 PVC Pipe?
Based on National Electrical Code (NEC) 352, Schedule 40 PVC Conduit Electrical Pipe is generally for electrical applications in walls, floors, and ceilings. Sometimes, it is also used underground, either in those areas exposed to sunlight or not.
If you will use this pipe for your water line, it is worth mentioning that it can absorb the temperature of the water up to 140 degrees F.
Furthermore, this type of pipe is made to perfectly handle fluid pressure applications, corrosive chemicals, and damaging materials. When you use this pipe and glue it using a standard medium, you are highly encouraged to glue it multiple times to secure the pipe.
Being the most affordable PVC pipe, this one is used for the following applications:
- Residential Plumbing
- Landscape Irrigation
- Pool and Spa Design
- Photography Laboratories
- Electrical wires in zoos or aquariums
- Misting Systems
- Potable Water Service
Technically, schedule 40 pipe can handle PSI ranging from 40 to 280. However, you have to understand that the internal diameter of the pipe can affect how much pressure can be held. As the pipe gets bigger in size, its inner diameter decreases.
What is a Schedule 80 PVC Pipe?
There is also this 80 PVC pipe schedule. Generally, schedule 80 PVC pipe is mostly used for areas in your home that are exposed to physical damage. Compared to the schedule 40 PVC pipe, this one is more durable.
It has thicker walls and can handle higher PSI about up to 450. Like the schedule 40 PVC, this one can also withstand high temperatures, pressures, and corrosive materials.
- Commercial Plumbing
- Chemical Processing
- Agriculture and Aquaculture
- Exposed Electrical Conduit
- Wastewater Treatment System
The size of the schedule 80 PVC pipe varies from ½ inch to 16 inches. Again, the bigger the size, the smaller the inside diameter.
Schedule 40 vs Schedule 80 PVC Pipe: How Do They Compare?
Of course, there will be days when you will have to choose between the schedule 40 PVC pipe and schedule 80 PVC pipes. If you wonder which of these two is better, you might want to consider the comparison which will be discussed in this section.
1. Wall Thickness and PSI
When it comes to wall thickness, the schedule 80 PVC pipe has the upper hand. This means that this type is thicker and stronger.
There are times when you mistake bigger schedule 40 PVC pipe sizes with schedule 80 PVC pipes. For you to understand better, the former are usually colored white and the latter are usually colored black.
Additionally, the schedule 40 PVC pipes are usually those you see outside small buildings or homes – the ones used for water drainage.
On the other hand, the schedule 80 PVC pipes are those you usually see in bigger buildings. Because of their thickness, many commercial and industrial buildings use these pipes.
2. Inside and Outside Diameter
For the inside diameter, the schedule 80 PVC pipe has a smaller one compared to the schedule 40 PVC pipe. This is because the former has a thicker wall.
For the outer diameter, both the schedule 40 and 80 PVC pipes have the same measurement.
3. Weight and Cost
If you wonder which of these two is heavier, it is safe to say that the schedule 80 PVC pipe is heavier. Again, this is because this type of pipe is thicker than the schedule 40 PVC pipe.
If you are buying from another area far from your hometown, you might as well consider the weight because shipping, specifically the schedule 80 PVC, is kind of costly.
For the general cost, schedule 80 PVC is more pricey as it is made with more PVC materials and material walls to handle higher pressures and temperatures.
When it comes to the installation, there is not much difference between the installation procedures of schedule 40 and 80 PVC pipes.
In fact, based on ASTM standards, you can combine these two schedules into one using normal fittings. However, it is important to remember that, when you combine these two in one line, you have to make sure that the pressure they get can be handled by both schedules.
If you combine them and make your schedule 40 PVC pipelines get higher pressure, this can cause damage.
We have already given an introduction about the colors of the schedule 40 and 80 PVC pipes. However, there are manufacturers that produce the same colors as these two.
Apart from the schedule 40 PVC pipe being white and the schedule 80 PVC pipe being gray or black, you can also see these pipes in green, blue, red, and orange.
Based on personal experience, when we were renovating our home’s kitchen area, the construction worker told us that it is cheaper to buy the red and orange ones.
Is Schedule 80 PVC Pipe Better?
Because schedule 80 PVC pipe is thicker and more durable, you might sometimes think that this one is better.
Unfortunately, you might be wrong with this kind of idea. There are some disadvantages when using schedule 80 PVC pipe, and some of these are the following:
- This pipe can cause reduced capacity. This means that it can restrict water and pressure flow. When this happens, you might fail to achieve quality and intact interior capacity as the inner diameter of schedule 80 PVC pipes will take much space.
- As we all know, schedule 80 PVC pipes are heavier. Aside from shipping costs, installation of this pipe type may require more manpower, effort, and time.
- Schedule 80 PVC pipes are more expensive but this does not mean that you should go for schedule 40 PVC pipes when you need the former.
Still, many plumbing experts always go for the schedule 80 PVC pipes in all plumbing applications because of the durability and less risk of breakage.
If you are repairing your home pipes on your own, you might want to focus on the pressure requirements when choosing the best PVC schedules.
You can always consider the price and choose the schedule 40 PVC pipe but, if what you need is 80, choosing the former might only make you pay more after some time.
How to Measure Your PVC Pipe?
For those who are doing home renovations, you may sometimes ask yourself what is the best PVC pipe that you can use.
Well, you cannot just simply choose between schedule 40 and 80 PVC pipe. Aside from considering the factors such as pressure, you must also measure your PVC pipe so you can have the best fittings for it.
To measure, first, you have to place the pipe with the plain end facing you. Then, you should measure the right and left exterior edges’ distances.
You can use a ruler but a tape measure is highly recommended.
After, note your measurements and take note of the outside diameter. Schedule PVC pipes with the closest measurement to your pipe will then be used.
Other Factors to Consider When Buying Schedules of Pipes
Aside from the cost, inner and outside diameter, and pressure, there are other factors that you should also consider before you buy your schedule PVC pipe.
First, you have to measure the length of the PVC pipe you need. If you are on a tight budget, you can go for the longer one and just cut the pipe. Doing this will allow you to use the other part of the pipe for the other areas in your home.
Second, you might also want to consider the location where you will place your pipes. If you are placing them exposed to the sun, considering the degree of heat in that area is vital.
Remember, too much heat may damage your pipe. Again, based on personal experience, because we had no knowledge about these schedules of pipes back then, we once bought a schedule 40 PVC pipe and placed it in our open garage area.
After some days, water started to leak and we found out that the pipe was damaged already.
Indeed, when doing home renovations, choosing the right schedules of pipes is essential.
There are PVC 40 and 80 schedules, and choosing which is better between these two depends on many factors such as pressure and size of your pipe.
Between these two, schedule 40 PVC pipes are cheaper. Generally, you can use it, but, once the pressure is too high and it cannot be handled, this can only damage your PVC pipe.