The main difference lies within the thickness. The thickness of schedule 20 is just enough to hold up for a couple of years. The thickness is much smaller than schedule 40 and easily bends out of shape.
Try crushing it with your hand, and you’ll succeed to some extent. This means it won’t hold up for a lifetime. However, with schedule 40, you can install it in your home and forget about it. Generations ahead of you won’t need to replace it since it’s super thick.
Moreover, you’ll usually find that schedule 40 pipes are white in color while schedule 20 are black.
What is schedule 20 used for?
These pipes provide good corrosion resistance and are perfect for plumbing and drainage systems. You can also install them in dust collection systems or vacuums in a plumbing supply house.
Pressure rating
Schedule 20 pipes are rated up to 200psi. This is more than you’ll need for a tank in a residential or commercial space. It can easily be used to transport water from the well to the home or from the main to the house.
The pressure rating tells us the maximum amount of pressure a pipe can bear at a certain temperature under normal conditions.
Where do you buy schedule 20?
You can easily find these at your nearest home depot. But it is becoming harder to find as it no longer meets the code requirements of construction.
But if you need it for other projects, head over to Mcdonnell Hardware and Feed. If you are lucky, you can also find some online.
Thin wall PVC
If you’re looking for particularly thin walls, it might be Schedule 30 you’re looking for. These are ideal for drainage applications where lightweight and non-toxic pipes are needed. You can also go with the classic 1” thin-wall PVC.
Schedule 80
This is the ultimate level of strength. You may find them beneath parking lots and other high-traffic locations.
It’s typically utilized in pump stations when you need a bit more strength than Schedule 40 PVC. Because it has a similar outer diameter as Schedule 40 PVC, you may use it with all Schedule 80 and 40 fittings.
Here’s the appropriate chart.
| Nominal size [inches] | Outside diameter [mm] | Outside diameter [inches] | Wall thickness [mm] | Wall thickness [inches] | Weight [kg/m] | Weight [lb/ft] |
| 1/8″ NPS6 | 10.3 | 0.41 | 2.41 | 0.095 | 0.47 | 0.31 |
| 1/4″ NPS8 | 13.7 | 0.54 | 3.02 | 0.119 | 0.8 | 0.54 |
| 3/8″ NPS10 | 17.1 | 0.68 | 3.2 | 0.126 | 1.1 | 0.74 |
| 1/2″ NPS15 | 21.3 | 0.84 | 3.73 | 0.147 | 1.62 | 1.09 |
| 3/4″ NPS20 | 26.7 | 1.05 | 3.91 | 0.154 | 2.2 | 1.47 |
| 1″ NPS25 | 33.4 | 1.32 | 4.55 | 0.179 | 3.24 | 2.17 |
| 1 1/4″ NPS32 | 42.2 | 1.66 | 4.85 | 0.191 | 4.47 | 3 |
| 1 1/2″ NPS40 | 48.3 | 1.9 | 5.08 | 0.2 | 5.41 | 3.63 |
| 2″ NPS50 | 60.3 | 2.375 | 5.54 | 0.218 | 7.48 | 5.02 |
| 2 1/2″ NPS65 | 73 | 2.875 | 7.01 | 0.276 | 11.41 | 7.66 |
| 3″ NPS80 | 88.9 | 3.5 | 7.62 | 0.3 | 15.27 | 10.25 |
| 3 1/2″ NPS90 | 101.6 | 4 | 8.08 | 0.318 | 18.63 | 12.5 |
| 4″ NPS100 | 114.3 | 4.5 | 8.56 | 0.337 | 22.32 | 14.98 |
| 5″ NPS125 | 141.3 | 5.563 | 9.53 | 0.375 | 30.97 | 20.78 |
| 6″ NPS150 | 168.3 | 6.625 | 10.97 | 0.432 | 42.56 | 28.57 |
| 8″ NPS200 | 219.1 | 8.625 | 12.7 | 0.5 | 64.64 | 43.39 |
| 10″ NPS250 | 273 | 10.75 | 15.09 | 0.594 | 96.01 | 64.43 |
| 12″ NPS300 | 323.8 | 12.75 | 17.48 | 0.688 | 132.08 | 88.63 |
| 14″ NPS350 | 355.6 | 14 | 19.05 | 0.75 | 158.1 | 106.13 |
| 16″ NPS400 | 406.4 | 16 | 21.44 | 0.844 | 203.53 | 136.61 |
| 18″ NPS450 | 457 | 18 | 23.83 | 0.938 | 254.55 | 170.92 |
| 20″ NPS500 | 508 | 20 | 26.19 | 1.031 | 311.17 | 208.87 |
| 24″ NPS600 | 610 | 24 | 30.96 | 1.125 | 442.08 | 296.58 |
Schedule 120
Its outer diameter can be as much as 24 inches. Tubes in this category have wall thicknesses ranging from 11.13mm to 46.02mm.
Different grades of carbon steel have varying pressure capabilities for the same tubing size. Many use them in applications ranging from low to high pressure. In most sectors, workers use them for gas and liquid transportation.
Carbon steels may be robust, but they are not recommended for corrosive applications. Its durability makes them suitable for use in the construction and automotive industries.
Here’s the appropriate chart.
| Nominal size [inches] | Outside diameter [mm] | Outside diameter [inches] | Wall thickness [mm] | Wall thickness [inches] | Weight [kg/m] | Weight [lb/ft] |
| 4″ NPS100 | 114.3 | 4.5 | 11.13 | 0.438 | 28.32 | 19 |
| 5″ NPS125 | 141.3 | 5.563 | 12.7 | 0.5 | 40.28 | 27.04 |
| 6″ NPS150 | 168.3 | 6.625 | 14.27 | 0.562 | 54.2 | 36.39 |
| 8″ NPS200 | 219.1 | 8.625 | 18.26 | 0.719 | 90.44 | 60.71 |
| 10″ NPS250 | 273 | 10.75 | 21.44 | 0.844 | 133.06 | 89.29 |
| 12″ NPS300 | 323.8 | 12.75 | 25.4 | 1 | 186.97 | 125.49 |
| 14″ NPS350 | 355.6 | 14 | 27.79 | 1.094 | 224.65 | 150.79 |
| 16″ NPS400 | 406.4 | 16 | 30.96 | 1.219 | 286.64 | 192.43 |
| 18″ NPS450 | 457 | 18 | 34.93 | 1.375 | 363.56 | 244.14 |
| 20″ NPS500 | 508 | 20 | 38.1 | 1.5 | 441.49 | 296.37 |
| 22″ NPS550 | 559 | 22 | 41.28 | 1.625 | 527.02 | 353.61 |
| 24″ NPS600 | 610 | 24 | 46.02 | 1.812 | 640.03 | 429.39 |
Schedule 40 vs. 80
Schedule 40 and 80 are the two most prevalent forms of this pipe. Schedule 40 PVC is often white, while 80 is typically dark gray and available in other colors.
Their design is the most significant distinction. The wall thickness of the Schedule 80 pipe is thicker. As a result, the tube is more stagnant and robust and can withstand more considerable pressure.
Schedule 40 is perhaps the most familiar to you. It’s the white pipe you see surrounding buildings for sewage, and it’s available at local hardware stores.
This pipe best serves drainage and irrigation. They’re also great for other cold-water systems. Schedule 40 PVC is sturdy and stiff, which makes it resistant to pressure.
History
Late in the nineteenth century, polyvinyl chloride was discovered. The newly-generated chemical gas, vinyl chloride, was exposed to sunlight.
Scientists observed that it underwent a chemical reaction that resulted in an off-white solid substance. This substance is now called polymerization. To understand this substance, I highly recommend you continue reading below:
How to Measure (4 Step Guide)
You should use the nominal scale to compute its measurements. Of course, you will need to base their measurements on their hand structures rather than accurate scale measurements. I will include a handy guide below to help you figure out what size you’ll need.
To further explain it, you will see a detailed guide below on how to measure them:
How to measure
Place the pipe on a hard surface with one end facing you.
Measure the distance between the right and left exterior edges of your pipe with a tape measure or ruler.
While measuring, keep your ruler as level as possible.
Now, pair “Your Measurement” with “Average OD.”
Choose your pipes depending on the Average OD of your measurements.
Remember that these measurements are for the exterior border, not the inside. Your inner measurements may vary depending on the pipe schedule you require.
