Nipple (plumbing)
Encyclopedia
In plumbing
and piping
, a nipple is a fitting, consisting of a short piece of
pipe
, usually provided with a male
pipe thread
at each end, for connecting two other fittings.
The length of the nipple is usually specified by the overall length with threads. It may have a hex section in the center for wrench to grasp. A "close nipple" has no unthreaded area; when screwed tightly between two female fittings, very little of the nipple remains exposed. A close nipple can only be unscrewed by gripping one threaded end with a pipe wrench
which will damage the threads and necessitate replacing the nipple, or by using a specialty tool known as a nipple wrench
(or known as an internal pipe wrench) which grips the inside of the pipe, leaving the threads undamaged. When the ends are of two different sizes it is called a reducer or unequal nipple.
A barrel nipple or a pipe nipple is one which is usually made from pipe and is threaded only at both ends.
Threads used on nipples are BSP
, BSPT
, NPT
, NPSM and rarely Metric.
Plumbing
Plumbing is the system of pipes and drains installed in a building for the distribution of potable drinking water and the removal of waterborne wastes, and the skilled trade of working with pipes, tubing and plumbing fixtures in such systems. A plumber is someone who installs or repairs piping...
and piping
Piping
Within industry, piping is a system of pipes used to convey fluids from one location to another. The engineering discipline of piping design studies the efficient transport of fluid....
, a nipple is a fitting, consisting of a short piece of
pipe
Pipe (material)
A pipe is a tubular section or hollow cylinder, usually but not necessarily of circular cross-section, used mainly to convey substances which can flow — liquids and gases , slurries, powders, masses of small solids...
, usually provided with a male
Gender of connectors and fasteners
In electrical and mechanical trades and manufacturing, each half of a pair of mating connectors or fasteners is conventionally assigned the designation male or female...
pipe thread
National pipe thread
National Pipe Thread Tapered Thread is a U.S. standard for tapered threads used on threaded pipes and fittings. The taper rate for all NPT threads is measured by the change of diameter over distance. The angle between the taper and the center axis of the pipe is 1° 47′ 24″...
at each end, for connecting two other fittings.
The length of the nipple is usually specified by the overall length with threads. It may have a hex section in the center for wrench to grasp. A "close nipple" has no unthreaded area; when screwed tightly between two female fittings, very little of the nipple remains exposed. A close nipple can only be unscrewed by gripping one threaded end with a pipe wrench
Pipe wrench
The pipe wrench is an adjustable wrench used for turning soft iron pipes and fittings with a rounded surface. The design of the adjustable jaw allows it to rock in the frame, such that any forward pressure on the handle tends to pull the jaws tighter together. Teeth angled in the direction of turn...
which will damage the threads and necessitate replacing the nipple, or by using a specialty tool known as a nipple wrench
Nipple wrench (plumbing)
In plumbing, a nipple wrench is often known as an inside pipe wrench.An eccentric toothed gear is mounted on a hexagonal shaft. The wrench is introduced inside the pipe . As the wrench is turned, the eccentric gear is forced to grip the inside of the pipe...
(or known as an internal pipe wrench) which grips the inside of the pipe, leaving the threads undamaged. When the ends are of two different sizes it is called a reducer or unequal nipple.
A barrel nipple or a pipe nipple is one which is usually made from pipe and is threaded only at both ends.
Threads used on nipples are BSP
British standard pipe thread
The British Standard Pipe thread is a family of standard screw thread types that has been adopted internationally for interconnecting and sealing pipe ends by mating an external with an internal thread.-Types:...
, BSPT
British standard pipe thread
The British Standard Pipe thread is a family of standard screw thread types that has been adopted internationally for interconnecting and sealing pipe ends by mating an external with an internal thread.-Types:...
, NPT
National pipe thread
National Pipe Thread Tapered Thread is a U.S. standard for tapered threads used on threaded pipes and fittings. The taper rate for all NPT threads is measured by the change of diameter over distance. The angle between the taper and the center axis of the pipe is 1° 47′ 24″...
, NPSM and rarely Metric.
Further reading
- ASTM A733-03 Standard Specification for Welded and Seamless Carbon Steel and Austenitic Stainless Steel Pipe Nipples.
- ASTM B687-99(2005)e1 Standard Specification for Brass, Copper, and Chromium-Plated Pipe Nipples.
- ASME B1.20.7 Hose Coupling Screw Threads, Inch. (Quote: The normal sequence of connections, in relation to the direction of flow, is from an externally threaded nipple into an internally threaded coupling)