Union nut (plumbing)

It is used to connect water metering equipment and fittings to pipelines of hot and cold water supply systems, in heat supply systems, in process pipelines that transport non-aggressive liquids. A cone connection has several advantages - due to the absence of additional sealing materials, a cone or spherical connection made on the basis of the "metal - metal" principle is more durable and durable, more resistant to changes in the ambient temperature and various chemical influences. This connection can be used with a slight deviation of the axes of the joined sections without loss of tightness. The threaded connection makes it possible to quickly fasten and connect or dismantle the pipeline and the regulating elements of the water supply or heating networks. The nut that is part of the connection can be used several times, for this it is necessary to replace the used (deformed) O-ring seal, this makes it possible to save on installation time and material costs. The use of "American" gives advantages over the use of a conventional coupling with a lock nut.

The most popular materials are cast iron, brass containing chromium and nickel, stainless steel, as well as combinations of polypropylene parts and stainless steel.

The connection consists of two cylindrical halves connected by a nut. One half forms an integral connection with the nut, while the nut can rotate freely, while the second half has a thread, so that when tightening the nut, it moves towards the first. The tightness of the connection can be achieved either due to the seal; the ends of the halves are parallel to each other, either due to a conical or spherical connection, when one half is driven into the other when tightened due to a small difference in diameters at the junction.

• it becomes possible to carry out installation work in hard-to-reach places, connecting reliably and firmly in uncomfortable and cramped conditions various parts of various piping systems.
• if an American is already installed at the place of work, it becomes possible to disassemble and assemble the connection without using any special plumbing tool.
• makes it possible to dismantle the line without rotating the pipe, which in most cases is very convenient.
• can be used in plumbing with a threaded socket connection, as well as in conjunction with polypropylene pipes.

• American - article from the Big Encyclopedic Polytechnical Dictionary

• Galkina A.E., Galkin P.A. Big Encyclopedia of Plumbing
• Saveliev A. Plumbing in the house. Installation works M. 2008
• Jacques M., Fedullo D., Gallosier T. Encyclopedia of Plumbing. Practical Guide M .: Omega, 2007