Pipe Fittings

Purpose of Pipe Fittings

Plumbing fittings have different shapes which allow rigid straight pipe to change both direction and diameter.

Elbows

Used to change the angle or direction of the pipe run. The most common elbows come in 90 degree and 45 degree turns. The sweep of the fitting describes how fast a transition or change in direction is made.

Street Elbows

One end of the fitting has male threads and the other end has female threads. Street elbows are common in galvanized steel and copper pipe. They are convenient because they do away with the need for a nipple and work well in tight quarters.

Tee or T-fittings

Allow for branch lines.
They are shaped like the letter T.
DWV tees are known as waste or sanitary Ts.
In these fittings the intersection is slightly curved in order to avoid clogs. Gradual bends are best for smooth flow of waste.

Couplings

Used to join two straight pieces of pipe of the same diameter.

Reducers

Used to join pipe of different diameters.
Galvanized steel reducers are called bell reducers because they look like a bell.
All reducers make a gradual transition between different diameters of pipe and therefore they take up considerable space

Bushings

Used to make the diameter of a pipe fitting smaller.
They differ from reducers in that they make abrupt changes in diameter and take very little space.
Two examples of galvanized steel bushings are
face bushings, which take the least amount of space, and
hex bushings which can be tightened with an adjustable wrench.

Unions

Used to join pieces of pipe where pipes cannot be turned or when a piece of equipment may have to be removed for maintenance or replacement.

Adaptor fittings
are used to change the end of a non-threaded pipe to male or female threads as needed. Adaptors are commonly used in copper and plastic plumbing jobs. For example adaptors are used to convert from a PVC glue connection to a threaded connection or
from a copper soldered connection to a threaded connection.
Male adapters and female adapters are both common.

Caps

Used to close the end of a dead end pipe.

Plugs

Close an opening on a pipefitting normally used for inspection and cleanout.

Nipples

Short lengths (under 12″) of pipe threaded at both ends.

Wyes

Pronounced like the letter Y
Used primarily to gain inside access to DWV systems.

Valves

Devices that control the flow of liquid or gas through or from a pipe.
Types of plumbing valves are:
compression valves,
ball valves,
sleeve-cartridge valves,
ceramic disc valves
and more

PVC Fittings

PVC fitting come in a wide variety of configurations.
They many be glued (S) or threaded (T) or both.
Glued fittings are referred to as “slip” fittings.
When specifying a PVC fitting the size and type of connection are specified. Some examples are:
¾” x ½” ST Ell – A reducing ell with a ¾” slip x ½” thread
¾” x ¾” x ½” SST Tee – A reducing tee with a threaded outlet
¾” x ½” SS Bushing = A bushing with slip connections.

Copper Tubing Fittings

Copper tubing use compression fittings.
Fittings are available to adapt from compression to IPS and from compression to soldered fittings.
Common fittings include couplings, ells, and tees.

Valves and Hose Bibs

Valves are used to control the flow of water or other fluids in a plumbing system.
Common types of valves include the following:
A gate valve is a valve situated between the point of connection and the rest of the plumbing system.
It usually remains wide open, but can be shut down in case repairs or additions have to be made to the system.
A gate valve is not designed to be opened and closed on a regular basis.

A check valve allows the fluid in the pipe to flow in one direction only.
Check valves are used in water wells to prevent the backflow of water.
There are two basic types: swing or flapper and lift check valves. Both work automatically.

A globe valve is a valve used when frequent adjustment of the flow rate is necessary.
It is a compression-type valve with a disk or washer that is compressed into a seat to form a tight seal. Repair is made by replacing the stem washer or disk.

A hose bib is a threaded exterior faucet that allows for the attachment of a garden hose or appliance hose.

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