PVC End Types Explained



 

If you've worked with PVC pipe for any length of time, you will know that there are many different PVC end types. From spigots to barbed inserts, the look and purpose of different PVC end types vary widely. For newcomers to the wide world of PVC, this may be daunting. However, this blog post will act as a guide and should answer any questions you may have about PVC end types. It may also serve as a refresher for seasoned veterans of piping. After reading this guide, PVC end types will no longer be a mystery!

Sockets and Spigots

pvc pipe white bushing and coupling 3/4 inch on white background socket and spigotTo understand these end types, you must first understand the term "slip" as it is used in PVC. Slip refers to the fact that there are no threads or barbs. To secure a slip fitting, glue or some other adhesive must be used. Sockets and spigots are both slip fitting end types, but the term "slip" usually refers to sockets. A socket is a fitting that simply goes over the end of a pipe. A 1" socket end will fit on a 1" pipe. These are extremely common. Many PVC couplings have socketed ends. A commonly used abbreviation for "socket" is "soc."

A spigot fits inside a socket, so it is the same size around as regular pipe. When you need to attach a fitting to another fitting, you use a spigot end. In their function, sockets are the female and spigots are the male. Spigot fittings are often called street fittings. The terms "street," "spg," and "spigot," are all the same thing and refer to spigot end fittings. The picture above shows a 1.5" coupling with socket ends and a 1.5" x 1" bushing with a spigot end.

Female and Male Threaded

male and female threads threading white pvc elbowsFemale and male threads are pretty self-explanatory. On a female-threaded fitting, the threads are on the inside of the fitting. On a male-threaded fitting, the threads are on the outside of the fitting. This means a male-threaded fitting can be screwed into a female-threaded fitting. These connections do not need glue. Teflon tape is enough to keep it sealed tight. Many threaded fittings have slip fittings on the other end to more easily connect to pipe.

When browsing female-threaded fittings, you may see the abbreviations "FPT" and "FIPT." These stand for "female pipe thread" and "female iron pipe thread." For male-threaded fittings, you will see the same abbreviations with an "M" instead of an "F" and, you guessed it, the "M" stands for "male." Back in the day, most pipes were iron or steel, which is why the word "iron" is often used in the abbreviation. This does not mean the part is made of iron! PVC pipe is simply made to be usable in metal pipelines. The picture above shows a 1.5" female-threaded elbow and a 1.5" male-threaded elbow.

Barbed Insert

barbed insert black pvc female threads on white backgroundConnecting hose to PVC pipe can be useful in irrigation and many other outdoor PVC applications. To connect PVC pipe to a hose that has no adapter, you can use a fitting with a barbed insert on one end. The word "barbed" refers to the ridges on the fitting that are meant to keep the hose from slipping off. To seal and secure a hose onto a barbed insert fitting, you must use a a clamp. Hose expands outwards, so glue doesn't work. When looking for parts, you will often see "barbed insert" shortened to "insert" or "inst." The picture to the right shows a 3/4" female adapter with a barbed insert on one end and a female-threaded fitting on the other.

Inside Connectors

Some fittings have spigot ends that fit inside pipe itself as if it was a socket fitting. These are pipe extenders and inside connectors. They are rare as they are only required for very specific uses. Click here for the full guide to these unique fittings.

Flange

black pvc flange with socket fitting on white backgroundFlange fittings are used when you want to easily take apart sections of a pipeline as they are bolted together. Flange fittings can be more expensive than others because of all the accessories required to make a strong connection. The other end of a flange fitting can be threaded or slip. Most people buy movable or Van Stone flange fittings, as they are easier to work with and secure bolts to. The picture to the right shows a 1" Van Stone slip flange with a slip end that fits straight onto PVC pipe or a spigot fitting.

SSS, SST, SS, ST, etc.

The abbreviations above are just four of the many combinations of "S" and "T" that can be used for PVC fittings. "S" refers to slip fittings, particularly socket fittings. "T" refers to threaded fittings, particularly female-threaded fittings. The number of letters in the abbreviation is how many ends the fitting has. So an SSS fitting would be a fitting with three slip fittings; this is usually a tee. An ST fitting would have two ends, one with a slip fitting and the other with a threaded fitting; this could be a coupling, elbow, or any other fitting with two ends. It is a simple system of categorizing PVC fittings with a large number of possible variations.


 

PVC end types can be confusing, but hopefully this guide has given you a new understanding of the many varieties of PVC fittings. If you have any more questions, feel free to ask us on our Twitter and Facebook pages!

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