Ultrasonic testing of fitting assembly

Abstract

Apparatus and method for determining relative and/or absolute axial position of a conduit end within a fluid coupling includes application of input ultrasonic energy in the form of transient shear waves and analyzing the reflected energy. Application of the input energy collected at different radial positions about a first axial location is used with wavelet based correlation techniques to better analyze the reflected energy signals. Quality of the abutment between the conduit end and a surface associated with the coupling may also be determined as a separate or combined feature of the axial position determination.

1 . A method for evaluating a pulled-up condition of a fitting of the type having a conduit assembled at one end to a fitting comprising a body, a nut, and a conduit gripping device, the method comprising the steps of:
 pulling up the fitting on the conduit to form a fitting assembly wherein the conduit gripping device forms an impression on the conduit;
 applying mechanical energy into the fitting assembly at a reference position; 
 detecting at said reference position return mechanical energy; and 
 determining whether the conduit gripping device is correctly installed based on axial position of said impression relative to said reference position. 
   
   
   
       2 . The method of  claim 1  comprising two conduit gripping devices. 
   
   
       3 . The method of  claim 2  wherein said conduit gripping devices comprise a front ferrule and back ferrule. 
   
   
       4 . The method of  claim 1  wherein the conduit, nut, body and conduit gripping device are formed from stainless steel. 
   
   
       5 . The method of  claim 1  wherein said impression comprises a deformation formed by the conduit gripping device biting into the conduit. 
   
   
       6 . The method of  claim 1  wherein said impression comprises a deformation of the conduit from a compression of the conduit gripping device against the conduit after pull-up. 
   
   
       7 . Apparatus for evaluating a fitting for conduits, the apparatus comprising:
 a fitting comprising a first component, a second component and at least one conduit gripping device;   a conduit assembled with the fitting to form a pulled-up fitting assembly, wherein the conduit gripping device forms an impression on the conduit after the fitting has been pulled-up;   first means to apply mechanical energy into the fitting assembly and to detect returned energy and produce a signal related thereto; and second means to determine axial position of the impression on the conduit based on said signal.   
   
   
       8 . The apparatus of  claim 7  wherein said first means comprises a transducer. 
   
   
       9 . The apparatus of  claim 8  wherein said transducer operates as both a source of the mechanical energy and a receiver of the mechanical energy. 
   
   
       10 . The apparatus of  claim 7  wherein said first means comprises an ultrasonic transducer. 
   
   
       11 . The apparatus of  claim 7  wherein said conduit gripping device comprises a ferrule. 
   
   
       12 . The apparatus of  claim 7  wherein the first component comprises a nut and the second component comprises a body, said nut and body being threadably joined together in the pulled up fitting assembly. 
   
   
       13 . The apparatus of  claim 12  wherein the conduit, body, nut and conduit gripping device comprise stainless steel. 
   
   
       14 . Apparatus for evaluating a fitting for conduits, the apparatus comprising:
 a fitting comprising a first component, a second component and at least one conduit gripping device;   a conduit assembled with the fitting to form a fitting assembly, wherein the conduit gripping device forms an impression on the conduit after the fitting has been pulled-up;   first means to apply mechanical energy into the fitting assembly and to detect return mechanical energy and produce a signal related thereto; and second means to determine whether the conduit gripping device is correctly installed based on said signal.   
   
   
       15 . The apparatus of  claim 14  wherein said mechanical energy comprises ultrasonic energy. 
   
   
       16 . Apparatus for evaluating a fitting for conduits, the apparatus comprising:
 a fitting comprising a first component, a second component and at least one conduit gripping device;   a conduit assembled to the fitting to form a fitting assembly, wherein the conduit gripping device forms an impression on the conduit after the fitting has been pulled-up;   a source adapted to apply mechanical energy into the fitting assembly; a receiver adapted to detect return mechanical energy and produce a signal related thereto; and an analyzer that determines whether the conduit gripping device is correctly installed based on said signal.   
   
   
       17 . A method for evaluating a pulled-up condition of a fitting of the type having a conduit assembled at one end to a fitting comprising a body, a nut, and a conduit gripping device, the method comprising the steps of:
 pulling up the fitting on the conduit to form a fitting assembly wherein the conduit gripping device forms an impression on the conduit;
 applying mechanical energy into the fitting assembly; 
 detecting return mechanical energy and producing a signal related thereto; and 
 determining whether the conduit gripping device is correctly installed based on said signal. 
   
   
   
       18 . The method of  claim 17  wherein said mechanical energy comprises ultrasonic energy waves. 
   
   
       19 . A method for evaluating a pulled-up condition of a fitting of the type having a conduit assembled at one end to a fitting comprising a body, a nut, and a conduit gripping device, the method comprising the steps of:
 pulling up the fitting on the conduit to form a fitting assembly wherein the conduit should have a deformation at an expected axial position on the conduit caused by compression of the gripping device when correctly installed;
 applying mechanical energy into the fitting assembly; 
 detecting return mechanical energy; and 
 determining whether the conduit gripping device is correctly installed based on the presence or absence of the deformation of the conduit at the expected axial position. 
   
   
   
       20 . The method of  claim 19  wherein said deformation comprises one or both of a bite and radial compression of the conduit gripping device against the conduit.