Obturating ring

An obturating ring is a ring of relatively soft material designed to obturate under pressure to form a seal. Obturating rings are often found in artillery and other ballistics applications, and similar devices are also used in other applications such as plumbing, like the olive in a compression fitting. The term "O-ring" is sometimes used to describe this kind of pressure seal.

For other uses, see Obturator.

Ballistics uses
Welin screw breech with mushroom-shaped de Bange obturator, and obturating ring behind

Obturating rings are common in artillery, where the steel or cast iron casing of the shell is too hard to practically deform to provide a tight seal for the propellant gases. An obturating ring which is called driving band made of a softer material is the standard solution for that problem. Mortar bombs also use obturating rings to provide a seal around the projectile. Recoilless rifles and some artillery use rings with a reverse impression of the rifling cut in them for a tighter seal even at very low pressures.

Another obturating ring may be used on sliding/falling breech-blocks from the opposite side of the chamber to provide a tight seal there if the charge is bagged and lacks a case (examples include early Krupp guns to Royal Ordnance L11 to M777). The obturating ring provides the sealing that would normally be provided by a cartridge case.

See also

References
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.