Control plate in a valve

Abstract

A control plate for effecting superior shut-off in a proportional control valve comprises a moveable disk-shaped element that has a flat surface, generally perpendicular to the valve axis of symmetry when closed, and translates toward or away from an orifice surrounded by a narrow lip or orifice ridge. Enhanced leak tightness in the valve shut-off condition is achieved by selectively incorporating into the control plate materials that are softer than the material comprising the orifice ridge.

What is claimed is: 
     
         1 . A valve control plate configured to sealingly engage a fluid conduit opening surrounded by a planar orifice ridge, the valve control plate comprising:
 a valve control plate body formed from a first material having a first hardness, the valve control plate body having a first surface configured to face toward the fluid conduit opening, the valve control plate body having a recess defined in the first surface of the valve control plate body; and   a valve seat insert formed from a second material having a second hardness that is less than the first hardness, the valve seat insert having a first surface configured to face toward the fluid conduit opening and sealingly engage the planar orifice ridge, and the valve seat insert being received in the recess.   
     
     
         2 . The valve control plate of  claim 1 , wherein the recess is one of a counterbore and a trepanned groove. 
     
     
         3 . The valve control plate of  claim 1 , wherein a volume of the second material is smaller than a volume of the first material. 
     
     
         4 . The valve control plate of  claim 3 , wherein the first material is a metal, the recess is a counterbore defined in the first surface of the valve control plate body, the second material is a polymer material, and the valve seat insert is retained in the counterbore by a retaining ring located at an outer periphery of the valve seat insert. 
     
     
         5 . The valve control plate of  claim 4 , wherein the valve seat insert is configured to engage a planar orifice ridge having a diameter of 4 mm or less. 
     
     
         6 . The valve control plate of  claim 1 , wherein the second material is a polymer material, the recess is a trepanned groove defined in the first surface of the valve control plate body, the valve seat insert is ring-shaped, and the first material is a metal. 
     
     
         7 . The valve control plate of  claim 6 , wherein the valve seat insert is retained in the trepanned groove by an inner retaining ring located at an inner periphery of the valve seat insert and an outer retaining ring located at an outer periphery of the valve seat insert. 
     
     
         8 . The valve control plate of  claim 7 , wherein the valve seat insert is configured to engage a planar orifice ridge having a diameter of 4 mm or greater. 
     
     
         9 . The valve control plate of  claim 6 , wherein the valve seat insert is retained in the trepanned groove by at least one of posts, columns, and bridges. 
     
     
         10 . The valve control plate of  claim 1 , wherein the first material is a first metal, the recess is a counterbore defined in the first surface of the control plate body, the second material is a second metal different from the first metal, and the valve seat insert is retained in the counterbore by welding the valve seat insert to the control plate body. 
     
     
         11 . The valve control plate of  claim 10 , wherein the valve seat insert is configured to engage a planar orifice ridge having a diameter of 4 mm or less. 
     
     
         12 . The valve control plate of  claim 1 , wherein a region of the first surface of the valve seat insert that sealingly engages the planar orifice ridge is planar. 
     
     
         13 . A valve bonnet for use with a control valve body, the control valve body being formed from a first material having a first hardness and having a fluid conduit opening surrounded by a planar orifice ridge, the valve bonnet comprising:
 a bonnet body;   a valve diaphragm in sealing engagement with the bonnet body at an outer periphery of the valve diaphragm;   a control shaft secured to the valve diaphragm, the control shaft having a shank projecting from the control shaft; and   a valve control plate secured to the shank, at least a portion of the valve control plate being formed from a second material having a second hardness that is less than the first hardness, the at least a portion of the valve control plate being configured to sealingly engage the planar orifice ridge.   
     
     
         14 . The valve bonnet of  claim 13 , wherein the at least a portion of the valve control plate is configured to engage a planar orifice ridge that is one of circular and non-circular. 
     
     
         15 . The valve bonnet of  claim 13 , wherein the valve diaphragm is formed integrally with the bonnet body, and the control shaft is integrally formed with the valve diaphragm. 
     
     
         16 . The valve bonnet of  claim 13 , wherein the diaphragm is formed separately from the bonnet body, and is welded to the bonnet body. 
     
     
         17 . The valve bonnet of  claim 13 , wherein the valve control plate further comprises a valve control plate body having a trepanned groove defined in the valve control plate body, and the at least a portion of the valve control plate is a valve seat insert that fills the trepanned groove. 
     
     
         18 . The valve bonnet of  claim 17 , wherein the valve seat insert is molded into the trepanned groove. 
     
     
         19 . The valve bonnet of  claim 18 , wherein the valve seat insert is retained in the trepanned groove by at least one of posts, columns, and bridges. 
     
     
         20 . A control valve comprising:
 a valve body having a fluid inlet conduit terminating at a first fluid conduit opening, a fluid outlet conduit commencing at a second fluid conduit opening, and an orifice ridge formed from a first material having a first hardness and surrounding the first fluid conduit opening;   a bonnet body secured to the valve body;   a valve diaphragm in sealing engagement with the bonnet body at an outer periphery of the valve diaphragm;   a control shaft secured to the valve diaphragm, and a shank projecting from the control shaft; and   a valve control plate secured to the shank, at least a portion of the valve control plate being formed from a second material having a second hardness that is less than the first hardness, the at least a portion of the valve control plate being configured to sealingly engage the orifice ridge.   
     
     
         21 . The control valve of  claim 20 , wherein the orifice ridge is one of circular and non-circular. 
     
     
         22 . The control valve of  claim 20 , wherein the valve control plate includes a valve control plate body having a trepanned groove defined in the valve control plate body, and the at least a portion of the valve control plate is a valve seat insert that fills the trepanned groove. 
     
     
         23 . The control valve of  claim 22 , wherein the valve seat insert is molded into the trepanned groove. 
     
     
         24 . The control valve of  claim 23 , wherein the valve seat insert is retained in the trepanned groove by at least one of posts, columns, and bridges.