Welded check valve

Abstract

Welded check valves include a poppet assembly, a spring, and a disc that contacts the spring. The disc may be held at a position away from a weld when forming the welded check valve. Embodiments may include retention features configured to allow one or more of the poppet assembly and disc to pass the retention features in an assembly orientation, and to retain those elements when they are in an operational orientation. Methods include inserting the poppet assembly, contacting the poppet assembly with a spring, inserting a disc, retaining the disc away from a weld side, and welding the check valve together. The poppet assembly and/or disc may pass one or more retaining features when inserted, and be retained by the retaining features when the check valve is operated. The weld may be a thermal weld.

What is claimed is: 
     
         1 - 20 . (canceled) 
     
     
         21 . A check valve including an internal passage, the check valve configured to control a fluid flow through the internal passage, the check valve comprising:
 (a) an internal assembly having,
 (i) a poppet assembly comprising a poppet and a poppet assembly disc, the poppet assembly disc includes one or more through holes extending axially through a flat surface of the poppet assembly disc, and the poppet assembly disc includes the outer edge of the poppet assembly; 
 (ii) a spring, contacting the poppet assembly at a first end; and 
 (iii) a disc including one or more through holes extending axially through a flat surface of the disc, the disc contacting the spring; 
   (b) a first outer piece having a first aperture and first opening opposite the first aperture;   (c) a second outer piece having a second aperture and a second opening opposite the second aperture, wherein the first outer piece and the second outer piece are connected by a weld at the first opening and the second opening to define an internal space for retaining the internal assembly; and   (d) a disc retaining feature located within the internal space, the retaining feature configured to selectively retain the disc in a position within the internal space away from the weld,   wherein the internal assembly is configured to obstruct a fluid flow through the internal passage in one direction and permit flow through the internal passage in an opposite direction, and the first outer piece includes an annular groove formed on an inner surface of the first outer piece.   
     
     
         22 . The check valve of  claim 21 , wherein the disc retaining feature is a snap ring configured to be inserted into the annular groove, wherein when the snap ring is inserted into the annular groove, the snap ring has an interior diameter that is smaller than an outer diameter of the disc. 
     
     
         23 . The check valve of  claim 21 , wherein the disc is configured to be inserted into the annular groove and the annular groove is the retaining feature. 
     
     
         24 . The check valve of  claim 21 , wherein the first outer piece, second outer piece, poppet assembly, and spring each comprise one or more fluoropolymers.