Pipe nipple is a section of a straight pipe, male threaded on both ends, which allows to connect two female threaded fittings together.
About Pipe Nipple TypesBrass pipe nipples are made from dezincification resistant red brass and approved for potable water use. They can be used in installation of filters, showers and other plumbing applications.
Black pipe nipples are manufactured from malleable iron and are commonly used for installation in closed loop hydronic heating applications and gas lines.
Dielectric pipe nipples are typically installed onto a water heater or a storage tank to prevent galvanic corrosion.