Abstract:
A fitting for use with metal tubing in a jacket, the fitting including: an adapter, the adapter having a tubular member defining a longitudinal passage having a longitudinal axis for fluid flow; a body for receiving the tubing, the body positioned opposite the adapter and aligned with the longitudinal axis; a sealing member positioned between the adapter and the body; a retainer positioned external to the sealing member, the retainer receiving the adapter and receiving the body; a first flange located near the adapter and a second flange located near the body; and a fastener for drawing the first flange and second flange towards each other.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The invention relates generally to piping systems and in particular to a fitting for use with a tubing containment system. Currently, flexible piping, such as corrugated stainless steel tubing, is used in a number of applications requiring primary and secondary containment. Various plumbing as well as local and federal mechanical codes and specifications require that certain types of installations of flexible piping be protected by a secondary containment system. Tubing containment systems exist in the art to contain fluids if the tubing fluids. One existing tubing containment system is disclosed in U.S. Pat. No. 7,004,510, the entire contents of which are incorporated herein by reference. A threaded fitting for use with a tubing containment system is disclosed in U.S. patent application Ser. No. 12/207,626, the entire contents of which are incorporated herein by reference. 
       SUMMARY 
       [0002]    Embodiments of the invention include a fitting for use with metal tubing in a jacket, the fitting comprising: an adapter, the adapter having a tubular member defining a longitudinal passage having a longitudinal axis for fluid flow; a body for receiving the tubing, the body positioned opposite the adapter and aligned with the longitudinal axis; a sealing member positioned between the adapter and the body; a retainer positioned external to the sealing member, the retainer receiving the adapter and receiving the body; a first flange located near the adapter and a second flange located near the body; and a fastener for drawing the first flange and second flange towards each other. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]      FIG. 1  is a cross-sectional view of an exemplary flanged fitting for use in a tubing containment system attached to tubing. 
           [0004]      FIG. 2  is a cross-sectional view of the adapter of  FIG. 1 . 
           [0005]      FIG. 3  is a cross-sectional view of the body of  FIG. 1 . 
           [0006]      FIG. 4  is an enlarged, cross-sectional view of the ferrule of  FIG. 1 . 
           [0007]      FIG. 5  is a cross-sectional view of a fitting in an alternate embodiment. 
           [0008]      FIG. 6  is an enlarged, cross-sectional view of a portion of  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0009]      FIG. 1  is a cross-sectional view of an exemplary flanged fitting coupled to a tubing containment system. The fitting includes an adapter  100  and a body  200 . Adapter  100  includes a longitudinal through passage  106  to allow fluid (gas, liquid, etc.) to flow. As described in U.S. Pat. Nos. 5,799,989, 6,079,749 and 6,428,052, adapter  100  interacts with a sealing member  300  to compress corrugated tubing between the adapter  100  and sealing member  300  to form a fluid tight seal. Sealing member  300  may be a formed by split ring washers, a collet or other member. Retainer  400  is used to keep the sealing member  300  in place and guide the body into position during use. A ferrule  500  engages the jacket  702  of the corrugated tubing  700  to mechanically secure the jacket  702  to body  200 . Ferrule  500  also creates fluid tight seal against body  200  as described in further detail herein. 
         [0010]      FIG. 2  is a cross-sectional view of the adapter  100  of  FIG. 1 . Adapter  100  includes a tubular member  102  defining through passage  106  along longitudinal axis  104 . A shoulder  108  extends away from tubular member  102 , and is generally perpendicular to longitudinal axis  104 . Flange  600  contacts shoulder  108  when the fitting is assembled as described herein. A guiding surface  110  tapers from the shoulder  108 , and has an oblique angle relative to the longitudinal axis  104  of the fitting. In an exemplary embodiment, the angle of the guiding surface  110  matches the angle of an inlet surface  402  on retainer  400 . Adapter  100  includes an o-ring groove  112  for receiving an o-ring that seals against the interior of retainer  400 . Adapter  100  includes an adapter sealing surface  114  that contacts the exposed corrugated tubing  700  and compresses the metal tubing  700  between the adapter sealing surface  114  and a sealing surface  302  on sealing member  300 . In an exemplary embodiment, the angle of the adapter sealing surface  114  matches the angle of the sealing surface on sealing member  300 . 
         [0011]      FIG. 3  is a cross-sectional view of the body  200  of  FIG. 1 . Body  200  includes an o-ring groove  204  formed on an exterior surface of the body at a first body end proximate the adapter  100 . An o-ring may be positioned in the o-ring groove  204  to provide an enhanced seal between the body  200  and the retainer  400 . Body  200  also includes features that provide for venting of fluid in the event of a fluid. Body  200  includes a vent opening  206  that extends through an exterior wall of body  200 . Vent opening  206  provides for egress of fluid leaking from tubing  700  ( FIG. 1 ). Sensors (not shown) may be placed in fluid communication with vent opening  206  for monitoring of leaking fluid. 
         [0012]    A ferrule  500  is positioned on a rear end of the body  200  and engages the jacket  702  of tubing  700  ( FIG. 1 ). The ferrule  500  is received in a frusto-conical annular recess  208  on the rear of the body  200  where tubing  700  enters the fitting. The recess  208  has a recess surface having an angle “a” relative to a longitudinal axis of the fitting,  104 . In an exemplary embodiment, angle “a” equals 30 degrees. 
         [0013]      FIG. 4  is an enlarged, cross-sectional view of the ferrule  500  of  FIG. 1 . Ferrule  500  has a dual tapered surface  502  having a first section  504  and a second section  506 . The first section  504  has a steep angle (e.g., 45 degrees) to define a sharp edge  510 . This edge  510  is driven into the tubing jacket  702  when the fitting is assembled as described in further detail herein. The second section  506  has a more shallow angle “b” (e.g., 20 degrees). By making angle “b” less than angle “a” (on the recess  208 ) the edge  510  of ferrule  500  is driven towards the centerline of the body, into the jacket  702 . Edge  510  engages jacket  702  and provides a mechanical attachment between the body  200  and the jacket  702 . This provides a fluid-tight, mechanical attachment to the jacket  702  to control axial extension of the hose assembly under pressure. Also, the compression of ferrule  500  into the frusto-conical annular recess  208  and also provides a fluid-tight, metal-to-metal seal. Jacket  702  may be similar to that described in U.S. patent application Ser. No. 12/207,626. 
         [0014]    In assembling the fitting to the tubing  700 , the tubing  700  is fed through flange  650 , ferrule  500 , and body  200 . The distal end of tubing  700  has the jacket  702  removed to expose at least one valley of the corrugated tubing  700 . Corrugated tubing  700  has an exterior surface of undulating peaks and valleys. Sealing member(s)  300  is placed in an exposed valley of corrugated tubing  700 . The tubing  700  is pulled back through the body  200  until the sealing member  300  contacts a shoulder  220 . 
         [0015]    Retainer  400  is slid over the sealing member  300 . Adapter  100  is inserted into the retainer  400 , guided by guiding surface  110  coacting with inlet surface  402 . Flange  600  is positioned around tubular member  102 . Fasteners (e.g., bolts)  800  pass though openings  602  in flange  600  and engage threads  652  in flange  650 . In exemplary embodiments, four bolts are used. 
         [0016]    As the bolts  800  are tightened, adapter sealing surface  114  contacts the exposed corrugated tubing  700  and compresses the metal tubing  700  between the adapter sealing surface  114  and a sealing surface  302  on sealing member  300 . As flange  600  and flange  650  are drawn towards each other, the compression of the metal tubing  700  between the adapter sealing surface  114  and the sealing surface  302  folds the metal tubing  700  to form two layers of metal between adapter sealing surface  114  and sealing surface  302 . This defines a metal-to-metal seal between the adapter  100  and tubing  700 . 
         [0017]    Further, as the bolts  800  are tightened, the ferrule  500  is driven into frusto-conical annular recess  208  in body  200 . As the angle “a” of the recess  208  is greater than the angle “b” of second section  506  of tapered surface  502 , the ferrule  500  is driven into the jacket  702 . The edge  510  of ferrule  500  engages the jacket  702  to provide a secure fluid tight, mechanical connection. The compression of the ferrule  500  into recess  208  forms a fluid-tight seal between ferrule  500  and body  200 . 
         [0018]      FIG. 5  is a cross-sectional view of a fitting  900  in an alternate embodiment. Many of the elements of fitting  900  are similar to those of fitting  100 , and bear the same reference numeral. Fitting  900  varies in that the adapter sealing surface  902  is different than adapter sealing surface  114 .  FIG. 6  is an enlarged view showing the adapter sealing surface  902 . Adapter sealing surface  902  has the same angle relative to the longitudinal axis  104  as sealing surface  302 . 
         [0019]    As shown in  FIG. 6 , the adapter sealing surface includes a cutaway  904  rendering the surface area of the adapter sealing surface  902  less than that of sealing surface  302 . Cutaway  904  includes a first wall  906  substantially parallel to longitudinal axis  104 . As second wall  908  is substantially perpendicular to longitudinal axis  104 . In use, bolts  800  are tightened driving the adapter  100  into body  200 . This compresses metal tubing  700  between the adapter sealing surface  902  and sealing surface  302  as shown in  FIG. 6 . As a peak of the metal tubing is compressed, the edge between sealing surface  902  and first wall  906  applies force to the tubing  700  to form an annular crimp  710  in the tubing  700 . This crimp serves as a line seal and accommodates imperfections in the tubing  700  due to weld seams, mechanical tolerances, etc. 
         [0020]    The tubing containment system may be used in a number of applications including direct underground burial, above ground outdoor use, indoor use at elevated pressure for safety and other secondary containment and sensing systems for petrochemical lines. 
         [0021]    While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.