Compression fittings are special type of coupling, usually used to connect two pipes or a pipe to a fixture or valve. A compression fitting tightens down a sleeve or ferrule over a joint to prevent leakage. These pipe fittings are very strong and reliable and can be put on using just a pair of wrenches. These fittings do not require any heating and go well even with wet pipes.
Compression fittings are ideal for household plumbing applications.
- Cast Iron
In cases, when compression fittings are used for joining pipes of two dissimilar materials, for example PVC and copper, they should be made of such appropriate materials that are perfect for the connection.
- Compression nut
- Compression ring or inner ring or “olive”, and
- Compression seat
How it Works?
As the name suggests, compression fitting applies a compressive force to the pipe and pipe fittings, thus forming a tight seal. In order to prevent leakage of fluids, the fitting is compressed against the pipe with a force that removes the presence of any space in between the joints.
- Type-A or non-manipulative fitting: These fittings are easy to install and do not require any modifications to the tubing. Type-A compression fittings are also known as olive and can be installed using an ordinary wrench for tightening the surrounding nut. These fittings are usually used for water connections.
- Type-B or manipulative fittings: Installation of Type-B fittings require flaring or belling the tubing. In order to remove this type of fitting, a specialized pulling tool is often used for siding the nut and olive away from the pipe or tube. The type-B fitting is mostly used for gas lines.
Compression fittings are globally used for plumbing applications for joining thin-walled pipes or two tubes together. These fittings are widely used for hot and cold water faucets; and toilet stop valves.
Guidelines for using Compression Fittings:
- Compression fittings should always be used with permanent or stationaryconnections. These fittings are designed in such a way that they restrict the movement of the pipe away from the fitting.
- While installing compression fittings, care should be taken not to over-tighten them. Special care should be taken while using plastic pipes. Because there is a point beyond which tightening a compression nut will no longer yield any gain.
- When plastic pipes are joined through a compression fitting, a plastic compression ring should always be used instead of a metal ring.
- Compression fittings should not be used with bent tubes or pipes.