A pipe nipple is a length of pipe used as a connection component. A standard threaded nipple has external threads at both ends so it can join internally threaded parts. The word does not by itself identify its length, thread standard, material or permitted service.
A pipe nipple is a length of pipe used as a connection component. A standard threaded nipple has external threads at both ends so it can join internally threaded parts. The word does not by itself identify its length, thread standard, material or permitted service.
Identify both connection ends
ASC's standard welded steel-nipple submittal specifies tapered NPT threads at both ends of that named series. Swagelok's SS-8-HN hex nipple separately lists two male NPT connections and its body material. Those examples identify particular products; they do not make NPT or one material universal to every part called a nipple.
A hex nipple includes wrench flats in its body. A pipe nipple with a smooth barrel has a different exterior shape. Check the complete part description rather than assuming that two male ends make their dimensions and ratings identical.
Our NPT thread entry explains the thread designation. The component name answers a different question: which connection piece is present in the assembly.
Keep nominal size and length separate
ASC's sheet gives pipe size, outside diameter and available nipple lengths in separate columns. Its listed close length also varies with size. A close designation does not supply one universal overall dimension.
The nominal pipe size entry explains why a size label differs from a measured outside diameter. Overall part length is also different from the exposed length after its ends engage the adjoining components.
Use the actual equipment drawing and connection requirements for the assembled distance. The tub-spout replacement guide covers that equipment-specific measurement task. A stock nipple length should not be substituted for the finished-wall measurement without checking the complete connection.
Retain material and service information
BrassCraft's water-stop instructions show a pipe nipple at the female iron-pipe inlet. Its compression, sweat and other inlet configurations have separate instructions. A threaded nipple is not a substitute for the smooth tube required by another connection type.
For a replacement, record both end standards, nominal size, material, finish and required length. Confirm the product's intended fluid, pressure, temperature and approvals with the actual system documents. Swagelok's selection guidance expressly requires the complete system, compatibility and ratings to be considered.
The word nipple does not demonstrate drinking-water approval or make an ordinary catalog part the correct replacement for a named appliance assembly. If the existing connection is corroded, concealed or cannot be isolated, have the component and surrounding joint assessed. The fixture-stop guide addresses the separate replacement procedure; this definition supplies no universal tightening or cut-and-thread recipe.