Patent Publication Number: US-2020284363-A1

Title: Axial flow check valve

Description:
BACKGROUND INFORMATION 
     Field 
     Embodiments of the disclosure relate generally to compressed air applications and more particularly to check valves having high axial flow capability and directly insertable into a flow line. 
     Background 
     Plumbing systems, particularly in industrial applications, often have long straight sections of piping in which minimal diametric variation and complexity is desirable and very short sections of piping in which a minimum length and clearance radius are available. Check valves for these applications typically require significant additional radius or length to accommodate required flows. 
     It is therefore desirable to provide an axial flow check valve which provides maximum axial flow but is insertable directly into even a very short section of pipe with minimal added circumference relative to the pipe. 
     SUMMARY 
     Embodiments disclosed herein provide a check valve employing a valve body with an inlet portion having integrated first threads to engage an inlet pipe fitting and an outlet portion having integrated second threads to engage an outlet pipe fitting. The valve body has an internal chamber with a plurality of longitudinal flanges extending radially inward, the longitudinal flanges forming axial flow channels therebetween. Each longitudinal flange terminates at a radial flange having a sealing face. A poppet having a cylindrical outer surface with a first diameter is configured for sliding engagement of a guide surface on a radial inner extent of each of the plurality of longitudinal flanges and a sealing surface configured to mate in a closed position with the sealing face of the radial flange. A spiral spring urges the poppet to the closed position. A retainer constrains the spiral spring and has a plurality of spokes with open sectors between the spokes aligning with the axial flow channels. 
     The features, functions, and advantages that have been discussed can be achieved independently in various embodiments of the present disclosure or may be combined in yet other embodiments further details of which can be seen with reference to the following description and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  are pictorial views from an opposite perspectives of an exemplary implementation of the axial flow check valve 
         FIGS. 2A-2C  are top, bottom and side views of the exemplary embodiment; 
         FIG. 3  is a detailed pictorial representation of the exemplary implementation in ⅓ section along lines A-A of  FIG. 2A ; 
         FIG. 4A  is a detailed pictorial representation of the exemplary implementation in ½ section along lines B-B of  FIG. 2A ; 
         FIG. 4B  is a side section view of the exemplary implementation in ½ section along lines B-B of  FIG. 2A ; 
         FIG. 5  is a detailed pictorial section view of the valve body along lines C-C of  FIG. 2B ; 
         FIG. 6  is a side section view of the implementation in ½ section along lines B-B of  FIG. 2A  in the closed position; 
         FIG. 7  is a detailed pictorial view of the poppet; and, 
         FIG. 8  is a detailed pictorial view of the retainer. 
     
    
    
     DETAILED DESCRIPTION 
     Implementations disclosed herein provide an axial flow check valve which may be inserted in a section of pipe with minimal diametric variation and minimal pipe transition length. Referring to the drawings,  FIGS. 1A and 1B  show pictorial views of an exemplary implementation of the axial flow check valve  10  with top, side and bottom views shown in  FIGS. 2A-2C . The axial flow check valve  10  has a body  12  which includes an inlet portion  14  having first integrated threads (for the exemplary implementation internal threads  15 ) and an outlet portion  16  having second integrated threads (for the exemplary implementation external threads  17 ). As seen in  FIG. 3 , the inlet portion  14  includes an inlet aperture  18  and engages an inlet pipe fitting (a pipe nipple  20  for the exemplary implementation) on the upstream portion of a pipe  22   a  in which the axial flow check valve  10  is inserted while the outlet portion  16  has an outlet aperture  24  and engages a outlet pipe fitting (a threaded socket  26  for the exemplary implementation) in the downstream portion of the pipe  22   b . The body  12  includes wrench flats  28 . With this configuration, the axial flow check valve  10  has no greater diameter than any axial fitting applied to the pipe and therefore does not impact the overall diameter of a pipe run. The internal and external threads may be reversed for the first and second integrated threads on alternative implementations. 
     As seen in  FIGS. 3 and 4A-4B  the axial flow check valve  10  has a poppet  30  positioned in an internal chamber  32  in the body  12 . The poppet  30  has a sealing surface  34  configured to mate on a sealing face  36  of a radial flange  38  in a closed position. The radial flange  38  is concentric to a flow orifice  40 . The body  12  incorporates a plurality of longitudinal flanges  42  (three in the exemplary implementation) extending radially inward into to the chamber  32 . Each longitudinal flange  42  has a guide surface  44  on a radial inner extent of the flange. The poppet  30  has a cylindrical outer surface  46  with a first diameter  48  having sliding engagement with the guide surfaces  44  which maintains the orientation of the poppet within the chamber  32  and alignment concentric to a longitudinal axis  49  of the axial flow check valve  10 . Details of the longitudinal flanges and radial flange in the cavity in the body  12  of the axial flow check valve  10  can be seen in  FIG. 5 . 
     The poppet  30  has a cylindrical protrusion  50  with a second diameter  52  less than the first diameter  48  and concentric with the longitudinal axis  49 . The cylindrical protrusion  50  is concentrically received in a spiral spring  54 . The spiral spring  54  engages a shoulder surface  55  extending between the cylindrical protrusion  50  and the cylindrical outer surface  46  of the poppet  30  to resiliently urge the poppet  30  to the closed position as seen in  FIG. 6 . A retainer  56  is constrained in the outlet aperture  24  and engages the spiral spring  54  to react flow force against the poppet  30 . The spiral spring is sized to compress under normal fluid flow through the axial flow check valve  10 , represented by arrow  58 , to allow the poppet  30  to be displaced to an open position. 
     The retainer  56  has a plurality of radial spokes  60 . For the exemplary embodiment the plurality of radial spokes is equal in number to and aligned with the plurality of longitudinal flanges  42 . Open sectors  62  between the radial spokes  60  provide axial outlet flow from the axial flow check valve  10 . A rim  64  of the retainer  56  is constrained in the outlet aperture  24  by a crimped lip  66  on a circumference  68  of the outlet portion  16 . The spokes  60  extend inward from the rim  64  to a dimple  70  sized to be concentrically received in the spiral spring  54  to radially constrain the spiral spring and maintain alignment of the spring concentric to the longitudinal axis  49 . While shown as extending inward or upstream in the exemplary implementation, the dimple  70  may extend outward or downstream. Details of the poppet and retainer  56  are seen in  FIGS. 7 and 8 . 
     The longitudinal flanges  42  form axial flow channels  72 . In the open position as seen in  FIGS. 3, 4A and 4B  flow passes around the poppet  30  through the axial flow channels  72  and exits through the open sectors  62  on the retainer. In the exemplary implementation, the axial flow channels  72  are aligned with the open sectors  62  of the retainer  56  for uninterrupted axial flow. With any cessation of flow, spiral spring  54  urges the poppet  30  into the closed position engaging sealing surface  34  with the sealing face  36  on the radial flange  38  of the body  12  preventing any back flow through the axial flow check valve  10 . Any additional back flow pressure is reacted by the shoulder surface  55  to further urge the sealing face  36  against the sealing surface  34  further enhance sealing of the poppet  30 . 
     Having now described various embodiments of the disclosure in detail as required by the patent statutes, those skilled in the art will recognize modifications and substitutions to the specific embodiments disclosed herein. Such modifications are within the scope and intent of the present disclosure as defined in the following claims.