PVC fittings are pieces of pipe used in plumbing/pipe systems to connect pipes or any section of pipes of the same size or different sizes and shapes in order to change the direction of flow, regulate flow, measure the flow, or distribute the water supply from the main pipe to different other pipes.
They attach to the pipe usually through a slip socket, thread, or plastic welding, and have a diameter given in either mm (millimeter) or inches. Although they are often used in plumbing systems, PVC pipe fittings are also usually used in several other applications including, gas and heating systems as well as in construction and manufacturing.
They come in many different kinds with each serving a particular purpose. In this guide, we’ll outline all the major types as well as their functions and possible applications. So, if you’re looking to expand your knowledge on PVC fittings, read on!
The following is a comprehensive list of the most commonly used PVC fittings. Each entry contains a short description of the fitting and the possible uses as well as applications for it.
PVC tee fittings feature three ends; two that are in a straight line and another on the middle/side that’s at a perpendicular (90-degree) angle. They resemble the shape of the letter “T” hence their name and they help connect three pipes at right angles. They allow you to split a mainline into two separate lines with a connection that’s at a 90-degree angle – that’s one inlet and two outlets, with the outlets positioned at 90-degree to the inlet (mainline connection).
They are also often used to connect two lines (secondary pipes) into one main line – combine two inlets into one outlet. They are very versatile and one of the most widely used types of PVC fittings in plumbing, especially for providing connection to multiple pipes of various diameters and changing the direction of the water.
These tees are often made from Schedule 40 PVC and most have slip socket ends, but there are also threaded versions. They as well come in different sizes, mainly equal (straight) and unequal (reducing). The equal tees are the most common – all three sides are similar in size/diameter. The unequal tees are less common and they feature a smaller branch (the 90-degree end on the side/middle) than the run pipe (two ends that are in a straight line).
Besides these two, there are other versions of PVC tee fittings which include:
Comes in various names like combi, combo wye, long-sweep wye, or tee-wye. All these refer to the same thing which is a tee that features a gradually curving central branch/connecting joint – a wye and an additional 1/8 bend (45 degrees), combined in one 90-degree unit. They’re used mainly in drainage systems to provide a smooth path that curves gradually in order to reduce the chances of clogs. The slight curve also allows a plumber to easily push a snake tool through the drainage system and to as well encourage water flow in direction of the drain.
This features a curved center section and it’s also used in drainage systems to primarily connect horizontal drains to vertical drains, including fixture trap arms. The center connection is usually to the pipe that leads to a trap (trap arm). It’s not for connecting a vertical drain line to a horizontal one since solids are likely to accumulate right at the bottom part of the junction which may cause a blockage.
Also known as a tee with diverter baffle, an end-outlet tee, or a waste tee, this typically connects waste lines/pipes right before they enter the trap. It has a baffle to help prevent water from one waste line from entering the other right at the connection.
Elbow fittings are connectors that are curved or made with an angle to allow you to change/divert the piping direction or flow direction between two pipes, particularly to get turned or avoid something in the way. They are mostly available in 90-and-45-degree angles. The 90-degree elbow is used if the change in direction needed is 90 degrees while the 45-degree elbow is used when the change in direction needed is 45 degrees.
There are also some unique elbows that have 60 or even 22.5 degrees angle, which allows you to direct your pipe system however you want it or to fit exactly in the location you want. Like tee fittings, the elbow fittings are made of Schedule 40 PVC material and most have slip socket ends, but the threaded and butt welding versions are available. They are also available in various sizes, mainly normal and reducer elbows.
For the normal ones, the two ends are similar in size while for the reducer elbows, they differ in size. There is also Long Radius (LR) elbows where the radius is around 1.5 times the diameter of the pipe and the Short Radius (LR) elbows where the radius is around 1.0 times the diameter of the pipe. There are elbows that feature a side outlet, as well – have three ends rather than two. These work almost similarly to a tee but with a bend. Other variations include seated elbows and double-seated elbows.
Cross fittings, as the name implies, are shaped like a cross or the standard plus sign. They contain four openings in four directions – four slip connections that meet at 90-degree angles. They are commonly used when creating a pipe framework out of Schedule 40 PVC pipe. They allow for the connection of four pipes/pipe sections meeting at a point. The pipes connect at 90-degree angles thereby forming a plus shape that greatly enhances the structural integrity of a framework by providing strength and support.
They also allow you to split a mainline into three different lines much like a tee, although a tee splits it into two directions. This means that you can disperse the water flow into different directions without really starting another set of piping. The cross fittings are usually made from Schedule 40 PVC and come in different styles which include Y cross, stere cross, equal cross, and unequal cross. The equal and unequal crosses are the most common and the difference between them is the size wherein equal crosses all the four ends are of similar size while in the unequal crosses one cross line (two ends) is smaller than the other.
Couplers or couplings are a very short length/part of a pipe or tube that’s applied in the piping system. They are generally one of the most simple and affordable types of PVC fittings. They are mainly used to connect two pieces of PVC pipe in order to continue a straight line and the connection is usually permanent – can’t be detached without damaging the pipes.
The couplings can also be used to join pipes to fittings in certain configurations and they can as well help to patch leaking or broken pipes. These fittings are made from Schedule 40 PVC material and are available in a wide range of diameters, from ¼ inches to 12 inches. They can connect pipes that are of the same diameter or different diameters like small PVC pipes to a large one or vice versa.
The couplings are available with either threaded (female-threaded) or slip ends. They also come in three main versions:
These have a simple, stepped-down profile. The ends feature the same connection method but their sizes are different. They are used to join pipes of dissimilar diameters, like extending an existing pipe where a small process feeder line is connected into a large supply circuit or a small diameter fitting is installed. They can also be used where repairing broken PVC pipes is needed. They are available in threaded or welded designs.
These are special coupling fittings that are designed for connecting existing PVC pipes. They are made up of three parts; the compression seat (body), the compression nut, and the compression ring (gasket ring). The couplings use pressure to tighten connections. The gasket or rubber seals are on each side to prevent leaking when connecting the two pipes. The rubber piece helps grab the pipe when inserted into the gasket, adding extra strength to the joint. They are often used for underground connections.
These are also known as repair couplings and are usually used for repairing a certain length of damaged PVC pipe. They generally allow up to about two inches of pipe to be removed and then repaired using one fitting. They are the most efficient option for repairing a burst pipe or leak. The coupling is deliberately built without any internal stop so that it can slip freely into place in very tight locations, like the repair of a PVC pipe with a small leak because of corrosion or freeze bursting, or a pipe that had to be cut temporarily due to some reason.
These fittings basically handle the job of two couplers and an extra pipe. They feature two pipes, arranged as one into another with the inner pipe able to slide up to various lengths. Hence, they can fix long-length damaged pipes. They are compatible with Schedule 120, 80, and 40 PVC.
Union fittings are very similar to couplings in terms of function as they are used to connect two pipes together. However, unlike couplings, these are semi-permanent. They can be detached when needed without damaging or deforming the pipes. They consist of three parts: a nut and male and female threaded ends. The female and male ends are assembled using the nuts, plus necessary pressure is applied to connect the joint.
These fittings are mainly helpful for maintaining the purpose of pipe or when creating systems that may require changing or updating at a later date, or that may need to be taken apart regularly, to move, inspect, or maintain them. The nut acts as a separator and the pairing ends are interchangeable hence allowing for easy detaching and changing in a short time.
The primary function of cap fittings is to stop the flow of water. They are put on an end of a PVC pipe or piping system with an opening that doesn’t need to connect anywhere or is not in use. They are a great solution too for pipes that you intend to expand on later. They also provide easy access to a piping system when needed.
They are available in both threaded end (female-threaded) and slip socket end, meaning they can go outside or around the pipe. The slip socket cap slides onto the PVC pipe while the threaded cap screws right onto the end of the PVC pipe, providing an even more secure fit. The caps are usually made from Schedule 40 PVC and their outside can be round, rectangular, square, I- or U-shaped. There are some that even have a handgrip.
Plugs basically function the same way as caps but they stop the flow of water in a fitting rather than in pipe-like caps. Due to this, they go inside the fitting which means they feature either a male threaded end or a spigot.
The ones with male-threaded ends screw into place, creating a tight seal without requiring any adhesive – no liquid or water leaks out of or into the system. They are easy to install and remove for replacement or future use of the pipe. The ones with the spigot end are simple to install too in the end part of an existing fitting, but they need an adhesive to ensure a watertight seal.
Similar to the caps, plug fittings are made of Schedule 40 PVC and are commonly used in PVC piping systems or pipes where a tight seal is required, but with some flexibility to allow for changing of the configuration or expansion of the system when needed.
Adapters are sometimes referred to as reducing couplings and are one of the most versatile PVC fittings. They are designed for use when you need to change or go from one end type of pipe to another to allow for the connection of pipes and fittings of different sizes. For instance, it can allow a fitting that has a slip socket to join/connect to a PVC pipe that has a threaded socket and vice versa.
These fittings are essential, especially when it comes to extending pipe runs or even terminating them. They are mostly available in threaded or slip socket ends, and some even have spigots. The threaded types can be female, male, or straight-threaded.
The male adapters have male threads (thread on the outside) while the female adapters have female threads (threads on the inside). One end of the adapter is plain where it’s glued, welded, or soldered to the plain pipe end. Generally, adapter fittings are very versatile and allow for connection to a wide variety of pipes and fittings of different sizes.
Bushings are more like adapters, but they are made for connecting pipes that have different diameters by mainly reducing the fitting – for instance, reducing a large-sized fitting to a small pipe. Note that they don’t reduce pipes as adapters do. Another unique thing about them is that they are typically threaded which actually sets them apart from other fittings like couplings which are also able to connect two pipes that are of different sizes.
The threading design allows for a watertight seal without using an adhesive product and also for different kinds of connections, plus makes maintenance as well as pipeline customization easier. Some do come with slip ends, although this is not always the case. The bushings are usually made from either Schedule 40 or Schedule 80 PVC.
A nipple is a small fitting that has two male-threaded ends that can fit inside two pipes, a pipe and a fitting, or a fitting and tubing or funnel. They are primarily used to connect two female-threaded ends in a PVC piping system, either when joining two pipes or connecting a fitting and a pipe. They can also be used for joining two fittings with a small distance.
They are commonly made with Schedule 80 PVC because they usually require a tight fit but they are as well compatible with Schedule 40 parts. In most cases, the threading also goes throughout the length of nipples which helps them provide very tight connections. The nipples also come in several varieties, including:
These are used to join tube fittings. They’re typically strong and can withstand extreme pressure surges, changes, and vibrations.
These have two threaded ends with a hexagonal center.
These are used to get water or other fluids through pipes of different sizes
These are short tubular nipples that have an external taper thread at both ends and are un-threaded in between
The close nipples
Also known as “running” nipples, these are threaded throughout both ends
Wyes fittings resemble the letter “Y” and they are made to connect three pipes. They are most commonly used to join vertical drain pipes to flat horizontal ones, which is different from tees as they are used to make vertical drain pipe connections. They allow the PVC pipes to change their elevations and also to branch out into drains or freshwater lines. The branch is at a 45-degree angle. It’s much smoother angling compared to tees, designed to reduce friction and turbulence to keep the water flow smooth. These fitting are generally used in drainage connections.
Flanges are round fittings that are almost disc-like and work by pressing two surfaces together using clamps, edges, bolts, or a compressive force in order to create a tight seal. Most flanges commonly use bolts to join the two surfaces together. They are used to connect pipes when an extremely tight bond is needed. They are equally used when you need to attach accessories as well as other items to a pipe. They can also be used to increase the strength of a pipe or stop the flow.
PVC flanges are generally available with threaded or slip ends and are usually made from Schedule 80 PVC due to the strength required of them. The Schedule 80 PVC flanges tend to be thicker and stronger compared to the more standard Schedule 40 variety. They are primarily used in industrial applications because of their ability to withstand high pressure. Flanges are also commonly used in residential systems, mostly at the base of a home toilet – they are used, particularly when mounting a toilet to the floor.
Reducers are pipe fitting components that reduce the size of water flow from large to small by reducing the size of pipe. They allow you to move from one pipe with a larger diameter to a smaller one. They can be of various types including reducer tee, reducer elbow, reducer cross, and reducer coupler among others. However, the two main types are concentric and eccentric reducers. The former is cone-shaped as it gradually decreases around the pipe which can lead to the accumulation of air, resulting in cavitation. The latter has one edge parallel to the connection pipe of which air accumulation isn’t possible.
PVC trap fittings come in a P, S, U, or J shape. They are usually fitted near a plumbing fixture like beneath the sink. The trap bend is fitted mainly to prevent the sewer gases from entering a building or your home. If the gases are drawn back into the house, then people could inhale foul smells, which may cause illnesses or it could even explode.
PVC ball valves are highly used in the plumbing market. They are used mainly to stop the flow of fluids (usually water) in a PVC piping system. They are popular in many applications since they are simple to work with and are pretty sturdy, ideal for use with various media. They come with a handle that requires a single quarter turn to switch the flow in the PVC piping system off or on.
The valves are available in two types. The first is the compact ball valve which is a one-piece ball valve that’s manufactured with threaded or glue ends. The other is the true union ball valve which features union ends in either threaded or socket type connections. The union valves are often used in industrial applications. They allow for easy in-line valve replacement or repair due to the union ends that they come manufactured with.
Clean-out fittings feature removable parts to allow access to the drains without undoing or removing the plumbing fixtures. They enable an auger/plumber’s snake tool to easily clean out a clogged drain. Since augers are limited in length, the clean-out fittings are usually placed inaccessible locations. Larger plumbing (drainage) systems tend to even have several clean-outs placed at regular intervals throughout the system, including outside the building. The clean-out fittings often have screw-in plugs or screw-on caps. They are also called “rodding eyes” due to the eye-shape cover plates which are commonly used on external versions.
There are many different types of PVC fittings in the market today, each designed to serve a unique purpose and application, and carry its advantages and disadvantages. Therefore, it’s crucial you ensure to choose the right fittings for the applications you plan on using them. Our list covers most of the common options and we’ve explained the function of each so that you have a better understanding of how and where to use them.
Besides choosing the correct fitting, you have to ensure you also choose or use the right pipe size and pipe schedule. Just like the PVC fittings, PVC pipes are available in a variety of sizes, so you want to ensure the part you purchase is or will be compatible with your existing piping.
PVC fittings and pipes generally utilize a nominal system for their standard sizing. In other words, all the parts that are of similar size are usually compatible with each other. For instance, all one-inch PVC fittings will fit on a one-inch PVC pipe regardless of its schedule. Therefore, when choosing your PVC fittings and pipes, nominal size should be your primary point of focus.
The other key consideration is the schedule of the pipes, which basically indicates the pipe’s thickness (thickness of the wall). The most common are schedule 80, 40, and 20. The schedule 40 PVC fittings and pipes are more common and are able to operate under both moderately high and low pressures. They are usually used for most water and gas applications within the home, although only in instances that don’t require a fitting or pipe rated for high pressure.
The schedule 80 PVC fittings and pipes are thicker and heavier compared to the rest but the outside diameter is the same. These are able to withstand high levels of pressure, way above and beyond what the schedule 40 can handle. Generally, as the schedule rating increases, the strength of the pipe also increases while the internal diameter decreases.
It’s important to know your area’s building codes to understand what kind of pipe and fitting schedule are needed. However, for safety, you should always choose the same schedule fittings as your existing pipes’ schedule. If the application requires schedule 80 PVC fittings or pipes, then you should not use schedule 40 as this could be dangerous.
It can cause damage to the house, appliances, or even yourself. For example, if a lower schedule pipe is used for an application that requires a higher schedule one, it can shatter into pieces and create projectiles that could be dangerous. So, you have to ensure you get PVC fittings and pipes that are of the right size and schedule.