Every year, up to 1 trillion gallons of household water gets wasted because of leaks. There are many things that can cause a leak, but one of the most common is improper installation.
When it comes to plumbing, there are two major things you’re working with: pipes and fittings. The pipes create a path for water to flow. The fittings connect the pipes together and allow you to customize your plumbing to suit your needs.
Install them the wrong way and you could wind up with a myriad of issues, such as the following:
- Recurring clogs
- Banging pipes
- Poor water quality
- Mold growth
The best thing you can do is learn how to do it right the first time. That means understanding the types of PVC pipes and fittings available to you, as well as how and when to use them.
Polyvinyl Chloride, or PVC, is a very common material for plumbing pipes. It’s lightweight, durable and easy to work with making it one of the best pipe materials for DIY plumbers.
- It also has a load of other benefits:
- Resistant to corrosion and impact damage
- Quiet even in high-pressure systems
- Doesn’t often freeze due to low heat conduction
- You can soft weld it with glue or cement instead of Sauder
It’s no wonder they’ve seen use in America since 1955.
PVC Versus CPVC
Chlorinated polyvinyl chloride (CPVC) is a lot like PVC. The main difference is that CPVC has a higher melting point than that of PVC.
CPVC can withstand temperatures up to 200 degrees Fahrenheit. PVC starts breaking down at 140 degrees. For this reason, PVC is only used for cold water pipes while CPVC gets used with both hot and cold water pipes.
CPVC can also manage higher pressure systems than PVC because it has a higher tensile strength.
Why not use CPVC for everything? There are many benefits, but you will also find that they can become quite expensive.
PVC costs about a fifth of what CPVC does.
PCV also has a couple more size and shape options than CPVC. You can get 10 and 20 foot long PVC pipes with both straight and bell-shaped ends. CPVC only come comes in 10-foot straight pieces.
Types of PVC Pipe: Schedule 40 Versus Schedule 80
PVC type is really more of a reference to its thickness, or Schedule, than anything. In household plumbing, you most often see Schedule 40 and Schedule 80 PVC pipes.
Both have the same outside diameter, but the Schedule 80’s inside diameter, or bore, is smaller. This means that the wall of a Schedule 40 pipe is thinner than that of a Schedule 80 pipe.
Schedule 80 pipes extra thickness means they can handle higher water pressure systems. Since Schedule 40 pipes are less expensive, you may want to use them in areas with low to no pressure like under a sink.
In a residential application, Schedule 40 will usually do fine. That said it’s important to know your highest pressure point to avoid damage to your pipes
A Note About Fitting Sizes
A pipe is not measured by its outside diameter. It’s always measured by its bore. Pipe fittings need a diameter that can fit over the outer diameter of the pipe, which is larger than its bore.
If suppliers were to size fittings and pipes according to these different sizes, things would get confusing fast.
For this reason, they use a nominal sizing chart that names fittings based on the pipe’s size, not actual size. If you have a pipe with a 3/4 inch bore, you’ll need a 3/4 inch fitting even though the fitting port is larger than that.
This PVC pipe size chart may help you in determining your needs.
Glossary of Terms for Fittings
Spigot: The end of a fitting that inserts into another fitting or pipe. You may also hear it called a male fitting.
Socket: The receiving end of a fitting. The socket, or hub, is the female counterpart to the male spigot.
Slip Socket: An unthreaded socket. You don’t have to screw this fitting on. It slips right over the male end of your pipe or fitting.
Types of PVC Fittings
There are many types of PVC fittings and each one has a job to do. These are the most important ones you need to know.
Tees: Tees connect three pipes together at right angles and have three ends and look like the letter, “T”. They’re often used to connect two secondary pipes to a mainline. Tees with slip socket ends are common, but you can get threaded tees as well.
Elbows: Elbows come in handy when you need to get around something that’s in the way.
Crosses: As the name implies, cross fittings like a cross or plus sign. Use them to connect four pipes together at 90-degree angles.
Couplings: Couplings couple pipes together in a straight line, usually permanently, with female threads or slip sockets. Many are adapters used to go from a larger pipe to a smaller pipe or vice versa.
Caps: Caps stop the flow of water. They are a perfect solution for pipes that don’t need to connect anywhere else or that you’ll expand on at a later time. You can get them with female-threaded or slip socket ends.
Plugs: Like caps, plugs stop the flow of water, but they do so in a fitting, not a pipe. They do so by fitting inside the fitting, so they come with either a spigot or a threaded male end.
Reducing Couplers: Reducing couplers are adapters used to change end types between two types. For example, it can allow a fitting with a slip socket to connect to a pipe with a threaded socket.
Nipples: Nipples have two male-threaded ends. They’re used to connect two pipes or fittings with female-threaded ends. Nipples are usually used with schedule 80 PVC because they need a tight fit, but you can use them with Schedule 40 PVC as well.
Connecting Pipes and Fittings
Creating a solid connection between PVC pipes and fittings is easy. Here is what you need to do to make it work properly.
1. Cut your pipe to length and make sure the end is flush.
If you don’t make a square cut, your pipe won’t have enough surface area for the cement to do its job. The best tool for the job is an inside pipe cutter with a diamond wheel. These tools cut the pipe from the inside out making them perfect for plumbing work where other cutting instruments can’t reach:
- Pipes running through the ceiling of a home
- Below floor level plumbing
- Plumbing work around swimming pools
- Replacing closet flanges
You can also use a fine-tooth handsaw or a power miter saw for plumbing in open areas.
2. Sand off burrs left from cutting the pipe for a smooth surface.
Burrs left on the inside of pipes slow the flow of water and catch debris. Burrs on the outside make it more difficult to get a solid fit. A curled sheet of 80-grit sandpaper will do a fine job.
3. Orient and mark pipes and fittings so you can tell which way they go.
Marking your fitting and pipe before applying the PVC cement makes it much easier to align your work. Once you apply the cement, you have a very small window of time before it bonds. Now that you have your marks, you can take them back apart.
4. Apply PVC Primer.
Spread PVC primer across the inner surface of the female fitting and the outer surface of the male pipe. This prepares the PVC surface for your cement application. Let it dry for about ten seconds.
5. Coat the same surfaces evenly with PVC cement.
Spread the cement evenly, but don’t apply too much. If you do, you’ll end up pushing it inside the pipe. Now you’re on a time table, so you’ll have to work quickly from here.
6. Insert the pipe into the fitting.
Stick the pipe in the fitting at about a quarter-turn from where you made your orientation marks. Now you can turn the pipe to line up your marks. Making this quarter-turn helps spread your cement to make a more solid joint.
7. Hold the pipe and fitting together for about 15 seconds.
If you don’t hold the pipe and fitting together until the cement creates a bond, the pipe may push out. If this happens, you’ll get stuck with a weak joint that may leak.
Ready to Get to Work?
Now that you know about the different types of PVC pipes and their fittings, its time to put your knowledge to the test.
Since 2008, our EzyGrind inside pipe cutters have helped people make true pipe cuts with ease. So you can tackle any job with ease, we offer diamond blade cutters in two sizes:
- 1 1/2″ (36mm): Perfect for cutting 1.5″ to 3″ Schedule 40 PVC Pipe
- 3 1/8″ (80mm): Ideal for use with 4″ to 6″ Schedule 40 PVC Pipe
They can also cut through HDPE and ABS pipes and are strong enough to cut concrete. Additionally, our Free Flow Guide Wheel technology will help you maintain safety and accuracy.
We design our tools for total satisfaction.
Please contact us anytime if you have questions about what we offer!