Lokring Connectors Can Replace Welded Connections
The unique metal-to-metal seal of the Lokring connection provides extraordinary sealing integrity in both liquid and gas services. Unlike other mechanically attached fittings, there are no elastomemeric or rubber seals, O-rings or gaskets which can degrade and leak over time from chemical attack, fire, vibration, temperature cycling, cold flow or loss of elasticity. As a result, fugitive emissions typical of leak-prone screwed or flanged connectors are eliminated.
The leak-free seal of a Lokring fitting is the result of Lokring(r) Technology Corporation's patented elastic strain pre-load (ESP(r)). During installation, the axial movement of the Lokring driver over the fitting body swages the body onto the pipe or tube surface, compressing the pipe/tube wall, first elastically and then plastically. The pipe/tube wall resists this swaging action, generating high unit compressive loads at the contact points between narrow sealing lands inside the fitting body and the pipe surface.
These contact stresses are sufficiently high to plastically yield the pipe/tube surface under the sealing lands, forming a perfect 360° circumferential, permanent, metal-to-metal seal between the pipe/tube and the fitting body. The driver, which experiences a small increase in diameter (elastic strain) during installation, exerts an elastic, radial preload on the metallic seals for the life of the connection.
No other connector (flanged or threaded) is capable of passing helium leak testing anywhere close to the level of a Lokring fitting. In fact, the fitting meets all criteria of a welded connection, except that no heat is required to make the connection.
Both stainless and carbon steel Lokring fittings are qualified to the requirements of the ANSI/ASME B31 pressure piping codes for pressure and fatigue design and materials of construction. Extensive mechanical and environmental testing has demonstrated the mechanical and sealing integrity of the Lokring connection in a wide range of applications and environmental conditions.
For more information, contact Gary Rose at Lokring Northeast, 3 Slater Road Cranston, RI 02920; tel. 401-463-4108; fax 401-463-6056 or e-mail gr@fwwebb.com.
