Pull-up by torque fitting with compressible member

Abstract

A ferrule type, flareless fitting is provided that may optionally be pulled-up to its assembled condition by torque rather than by turns. In one embodiment, at least one fitting component includes a structure that facilitates pull-up by torque and allows the fitting to be remade. The structure may take a wide variety of different forms. Examples of fitting component structures that facilitate pull-up by torque and allow the fitting to be remade include, but are not limited to, deformable or compressible devices or structures that are configured to increase the torque required to further tighten the fitting components when the fitting is properly pulled up, resiliently deformable structures that bias a tube gripping device into engagement with a conduit when the fitting is remade to an initial pull-up position, and plastically deformable retaining structures that maintain a tube gripping device in sealing engagement with a conduit when a fitting is disassembled.

1 . A conduit fitting for a conduit end, comprising:
 a first coupling member comprising a threaded body having a camming surface;   a second coupling member comprising a threaded nut having a drive surface, wherein said second coupling member and said first coupling member when joined together provide an internal space;   a conduit gripping device disposed in said internal space between said first coupling member and said second coupling member such that when the conduit fitting is pulled up on an end portion of a conduit by relative axial translation between said first coupling member and said second coupling member to an initial pulled-up position said conduit gripping device will grip and seal the conduit;   a metal deformable structure disposed between an external surface of said first coupling member and an external surface of said second coupling member such that assembly of said first coupling member with said second coupling member to said initial pulled up position causes said metal deformable structure to be compressed between said external surface of said first coupling member and said external surface of said second coupling member to provide an indication of completed pull-up to said initial pulled-up position.   
     
     
         2 . The conduit fitting of  claim 1  wherein deformation of the deformable structure facilitates further axial advance of the first coupling member relatively toward the second coupling member beyond said initial pulled-up position. 
     
     
         3 . The conduit fitting of  claim 2  wherein said further axial advance permits remake of said fitting. 
     
     
         4 . The conduit fitting of  claim 1  wherein assembly of said first coupling member and said second coupling member comprises rotating the first coupling member with respect to the second coupling member, and wherein said indication of completed pull-up is a torque required to continue rotating the first coupling member with respect to the second coupling member. 
     
     
         5 . The conduit fitting of  claim 4  wherein deformation of the deformable structure facilitates further axial advance of the first coupling member relatively toward the second coupling member beyond said initial pulled-up position, and said further axial advance permits remake of said fitting by applying said torque that provides said indication of completed pull-up to said initial pulled-up position. 
     
     
         6 . The conduit fitting of  claim 1  wherein deformable structure is elastically deformed to provide said indication of completed pull-up. 
     
     
         7 . The conduit fitting of  claim 1  wherein deformable structure is plastically deformed to provide said indication of completed pull-up. 
     
     
         8 . The conduit fitting of  claim 1  wherein the deformable structure is integrally formed with one of the first and second coupling members. 
     
     
         9 . The conduit fitting of  claim 1  wherein the deformable structure is a separate member. 
     
     
         10 . The conduit fitting of  claim 1  wherein the deformable structure is integrally formed with the conduit gripping device. 
     
     
         11 . The conduit fitting of  claim 1  wherein the deformable structure comprises a Belleville washer. 
     
     
         12 . A method of assembling a conduit fitting, comprising:
 joining a first coupling member with a second coupling member such that a conduit gripping device is disposed between said first coupling member and said second coupling member;   deforming a structure between an internal surface of the second coupling member and the first coupling member to provide an indication of completed pull-up;   wherein completed pull-up of said first coupling member with said second coupling member causes said conduit gripping device to grip and seal the conduit.   
     
     
         13 . The method of  claim 12  further comprising remaking the fitting by further axially advancing the first coupling member relatively toward the second coupling member beyond an initial completed pull-up position by further deforming said structure. 
     
     
         14 . The method of  claim 12  wherein said structure is elastically deformed to provide said indication of completed pull-up. 
     
     
         15 . The conduit fitting of  claim 12  wherein said structure is plastically deformed to provide said indication of completed pull-up. 
     
     
         16 . A conduit fitting for a conduit end, comprising:
 a first coupling member;   a second coupling member joined with said first coupling member;   a conduit gripping device disposed between said first coupling member and said second coupling member such that assembly of said first coupling member with said second coupling member to an initial pulled-up position causes said conduit gripping device to grip and seal the conduit;   a deformable structure assembled in the conduit fitting such that the deformable structure is elastically deformed by assembly of the first coupling member with the second coupling member to said initial pulled-up position;   wherein the deformable structure is configured to bias the conduit and the conduit gripping device into engagement with one another to cause said conduit gripping device to grip and seal the conduit when the fitting is remade to said initial pulled-up position.   
     
     
         17 . The conduit fitting of  claim 16  wherein the deformable structure is compressed between the first coupling member and the conduit gripping device when the fitting is in the initial pulled-up position to bias the conduit gripping device into engagement with the conduit. 
     
     
         18 . The conduit fitting of  claim 16  wherein the deformable structure is compressed between the second coupling member and the conduit when the fitting is in the initial pulled-up position to bias the conduit into engagement with the conduit gripping device. 
     
     
         19 . The conduit fitting of  claim 16  further comprising a structure that causes torque required to axially advance the first fitting component with respect to the second fitting component to sharply increase at said initial pulled-up position and thereby provide an indication that the fitting has reached the initial pulled-up position. 
     
     
         20 . The conduit fitting of  claim 19  wherein the structure that causes torque to increase at the initial pulled-up position allows axial advance of the first fitting component relative to the second fitting component past the initial pulled-up position. 
     
     
         21 . The conduit fitting of  claim 20  wherein the structure that causes torque to increase at the initial pulled-up position comprises an inclined surface. 
     
     
         22 . The conduit fitting of  claim 20  wherein the structure that causes torque to increase at the initial pulled-up position comprises a second compressible member. 
     
     
         23 . The conduit fitting of  claim 20  further comprising a positive stop structure that limits axial advance of the first fitting component with respect to the second fitting component to said initial pulled-up position. 
     
     
         24 - 41 . (canceled)