FITTING WITH SEPARABLE GRIPPING DEVICE FOR PIPE AND TUBE

• Main Authors: WILLIAMS PETER, BENNETT MARK A
• Format: Patent
• Language: English
• Published: 18.09.2006
• Subjects: BLASTING; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; JOINTS OR FITTINGS FOR PIPES; LIGHTING; MEANS FOR THERMAL INSULATION IN GENERAL; MECHANICAL ENGINEERING; PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; THERMAL INSULATION IN GENERAL; WEAPONS

A tube fitting for a tube end has a female threaded member that cooperates with a male threaded member. The female member includes a tube gripping device (80) in the form of a gripping ring or ferrule that is attached to the female member by a frangible web (95). Upon a partial pull-up the ferrule (80) engages a camming surface (88) on the male threaded member and breaks off or separates from the female threaded member to become a separate piece so that the fitting then functions as a single ferrule tube fitting. Additional features include a steep camming angle on the camming surface to cause the ferrule (80) to grip the tube end with a bite-type action and to form a primary seal between the camming surface (88) and a front end of the separated ferrule. The ferrule front end, and optionally the entire female threaded member including the initially integral tube gripping device, are hardened to have a hardness ratio that is at least about 3.3 times the hardness of the material of the tube end on the Vickers scale.