Pipe fittings are any type of component used either to join one piece of pipe to another or something to be inserted between two pieces of pipe (like a T-piece that joins three pieces of pipe or a small needle valve inserted into a line of pipe). Generally speaking, these pipe fittings will be made from the same material as the pipe itself.
This could be plastic, copper, iron, brass, steel (usually a stainless grade) or any one of the exotic alloys. The material is selected for compatibility with the environment both within and outside the pipe. For example, pipe carrying water from your house to a hose point in the back yard could well be made of a special plastic such as PVC, GRE, or, HDPE. However, when pipe is used for more critical purposes that often involve very high pressures, dangerous fluids and/or high temperatures a stronger material will have to be specified to suit the application.
As a general rule of thumb, we tend to say that “plumbing” deals with the less arduous domestic style applications and “piping” covers those with higher performance. However, the term “pipe fittings” is commonly used in both plumbing and piping.
These are many types of pipe or plumbing fitting where the connection is of a threaded type that is sealed by tightening onto an inner metal ferrule. Like all fittings, they are available in materials to match those used for the pipe. Plumbers in particular appreciate the ease with which they can complete leak tight connections when using compression fittings.
Copper, Bronze And Brass
Copper is still used for some pipe or tubing applications but, in general, the plumbing trade has taken to brass as their most used alternative to plastic piping. Brass is an alloy of copper and zinc that should not be confused with bronze which is copper alloyed with tin. Both brass and bronze can have other metals added to the alloy mix to produce required properties in the resulting metal.
One of the reasons for popularity of brass pipe and associated Brass Compression Fittings is the germicidal properties inherent in the copper content which allows brass to be used on drinking water distribution pipes. NOTE – some brass has lead in the alloy and it is necessary these days to check for lead free brass when installing it on most water systems.
Brass is also a malleable metal which can be easily bent. Because of this deformability, most of the ferrules in many compression fittings will be brass or copper even if they are not totally Brass Compression Fittings. Furthermore, brass’s relatively low melting point makes it easy to braze or solder.