What Does Compression Ring Mean?
A compression ring is the seal that prevents leaks from pipe segments that have a bell-shaped opening at one end. When fitting sections of a pipe together, the smaller, male end of one section of pipe is fitted into the bell-shape of another to form the pipe string. The compression ring, when attached to the male, spigot end of the pipe section, forms a seal between the two sections, acting like the O-ring around a piston in an automobile engine.
Trenchlesspedia Explains Compression Ring
As part of the assembly process, a compression ring is fitted to the
male end before pressing the male end into place in the bell.
Pressing the joints of pipe together compresses the compression ring to
form a seal in the joint.
Compression ring seals are used in any pipe with a bell end, including lead drain pipes, such as those used in hospital laboratories. Orangeburg clay pipes used for street level sewer piping - most of which have been phased out after more than 100 years of reliable use, have been replaced with pipes made from materials less likely to leak in the short term - and PVC bell-joint piping used for newer sewer lines.
The compression seal is a mechanical seal. It relies solely on the relationship of the seal to the male spigot end of the pipe section and the mechanical process of inserting the seal and spigot end into the female bell end of the adjoining pipe. When the spigot end is inserted into the bell end, the ring is compressed between the two sections to form a stable seal between the outer wall of the spigot end and the inner wall of the bell end, acting like the O-ring around a piston.
Spigot and bell-joint piping can come in many forms and materials for almost any use. Likewise, compression ring seals come in a variety of materials. For example, lead seals are used with cast iron piping. Rubber or plastic seals may be used with PVC or plastic piping. Determining which seal to use depends on the type of pipe required for the particular application.