Reducing flow noise in a refrigerant expansion valve

Abstract

A combination thermally responsive refrigerant expansion valve with integral electrically operated inlet shutoff valve having an inlet shutoff valve seat surrounded by a flow diffuser which eliminates undesirable flow noise. In the preferred embodiment the diffuser comprises a plurality of radially extending flow channels formed adjacent the inlet shutoff valve seat integrally in a one-piece valve seat member.

1 . A thermally responsive expansion valve assembly having an electrically operated shutoff valve in the inlet thereof comprising: 
 (a) a valve body having an inlet and outlet and an expansion valve member moveable by an operating member adapted for connection to a thermally responsive element for controlling flow between the inlet and outlet;    (b) a shutoff valve member disposed between the main valve member and the inlet;    (c) a valve seat member disposed adjacent said shutoff valve member, said valve seat member having an annular seating surface and a diffuser disposed between said inlet and said annular seating surface; and,    (d) a solenoid operator attached to said body and having an armature operably connected for effecting movement of said shutoff valve member upon energization of the solenoid.    
     
     
         2 . The valve assembly defined in  claim 1 , wherein said diffuser includes plurality of radially extending passages surrounding said annular seating surface.  
     
     
         3 . The valve assembly defined in  claim 1 , further comprising a pilot valve member operable, upon energization of the solenoid, for opening a pilot passage through said shutoff valve member.  
     
     
         4 . The valve assembly defined in  claim 1 , wherein said annular seating surface and said diffuser are formed integrally in a one piece member.  
     
     
         5 . The valve assembly defined in  claim 1 , wherein said valve seat member has an inverted cup-shaped configuration and said diffuser comprises a plurality of radially extending channels formed on the closed end thereof surrounding said annular seating surface.  
     
     
         6 . A method of making a thermally responsive expansion valve assembly having an electrically operated shutoff valve in the inlet thereof comprising: 
 (a) disposing an expansion valve member moveably in a valve body and disposing an operating member from a thermally responsive unit in contact with the expansion valve member, and forming an inlet and outlet in the body communicating with the expansion valve member;    (b) disposing a shutoff valve member and an annular valve seat between the expansion valve member and the inlet;    (c) disposing a diffuser adjacent said annular valve seat on the upstream side thereof; and,    (d) disposing a solenoid operator on said valve body and energizing the solenoid and moving the shutoff valve member with the solenoid armature.    
     
     
         7 . The method defined in  claim 6 , wherein the step of disposing a diffuser includes forming a plurality of radially extending passages surrounding said annular valve sent.  
     
     
         8 . The method defined in  claim 6 , wherein the step of disposing an inlet valve member includes forming a pilot passage in the inlet valve member and disposing a pilot valve therewith.