Tolerance rings for pipe in pipe systems

Citation

(2003), "Tolerance rings for pipe in pipe systems", Anti-Corrosion Methods and Materials, Vol. 50 No. 1. https://doi.org/10.1108/acmm.2003.12850aad.005

Tolerance rings for pipe in pipe systems

Tolerance rings for pipe in pipe systems

Keywords: Pipelines, Tolerance rings

Numerous pipeline production applications call for a pipe of one material to be fixed inside an outer casing of a different type. Such “pipe in pipe” systems may use fixing methods ranging from loose insertion to heat shrinking, depending on applications and the characteristics of the external environment and the nature of the fluid to be conveyed. An effective and versatile alternative now attracting attention is to use a special type of spring fastener called a tolerance ring (Plate 3).

Explains Roger Cornwell of tolerance ring manufacturer Rencol: “These high precision fasteners are specifically designed for joining annular components. The fasteners take the form of an engineered ring which has wave forms around the circumference. These wave forms locate against the two surfaces to be joined to create a high performance interference fit. The rings are simply press- fit into position – a process which can be carried out manually or automatically, depending on the production environment.”

Plate 3 Numerous pipeline production applications call for a pipe of one material to be fixed inside an outer casing of a different type. Such “pipe in pipe” systems may use fixing methods ranging from loose insertion to heat shrinking. An effective and versatile alternative now attracting attention is to use a special type of spring fastener called a tolerance ring

The exact ring specification can reportedly be very precisely tailored to the application, through material selection and by modifying the pitch of the wave forms. Rings can be made from as small as 3 or 4 mm in diameter up to and beyond a metre.

This type of joint is said to readily accommodate differential thermal expansion and can be specified to withstand extreme temperature ranges without loss of performance. Because the rings are made from metal they can also conduct heat, when required.

Says Roger Cornwell: “Whilst pipeline performance criteria are generally demanding, they are no more so than those called for within the vehicle industry where tolerance rings are extensively used in such key locations as steering column collapse mechanisms, torque control devices and bearing mounts. Tiny rings are even used to mount actuator arms in computer hard disk drives which must function faultlessly for years.”

Details available from: Rencol Tolerance Rings, Tel: +44 (0)117 938 1700.