Control valve with integrated insert providing valve seat and plug guides

Abstract

A control valve for regulating flow of fluids has an actuator located in a control chamber connected to a valve body. The valve body defines a flow passageway passing through an opening. A plug is associated with the actuator such that movement of the actuator from a retracted position towards an extended position displaces the plug towards the opening. The valve also includes a guide-and-seat insert which provides a valve seat interconnected with an attachment collar via a number of plug guides. When the plug is displaced by the actuator, the plug slides in contact with at least two of the plug guides. When the actuator moves to its extended position, the plug closes against the closure surface of the valve seat so as to block the passage of fluid from an inlet to an outlet of the valve.

1 . A control valve for regulating flow of fluids comprising:
 (a) a body having an inlet, an outlet and a passageway through which the fluid passes from said inlet to said outlet, said passageway passing through an opening;   (b) an actuator located in a control chamber connected to said body and configured to move along an axis through a range of motion from a retracted position to an extended position;   (c) a plug associated with said actuator such that movement of said actuator from said retracted position towards said extended position displaces said plug towards said opening, said plug being mechanically linked to a valve stem that is slidingly supported relative to one of said body and said control chamber by a linear bearing; and   (d) a guide-and-seat insert including:
 (i) a valve seat configured to seal against said opening and to provide a closure surface against which said plug closes, 
 (ii) a plurality of plug guides integrally formed with said valve seat and extending from said seat towards said control chamber, and 
 (iii) a collar attached to or integrally formed with said plurality of plug guides and configured for clamping against an internal surface of said control valve so as to clamp said valve seat against said opening, 
   such that, when said plug is displaced by said actuator, said plug moves in sliding engagement with at least two of said plug guides, and such that, when said actuator moves to said extended position, said plug closes against said closure surface of said valve seat so as to block the passage of fluid from said inlet to said outlet,   and wherein said plurality of plug guides are deployed such that, under forward flow conditions from said inlet to said outlet, drag forces acting on said plug are opposed by three-point support of said plug provided by said linear bearing and two of said plug guides.   
   
   
       2 . The control valve of  claim 1 , wherein said collar is integrally formed with said plurality of plug guides. 
   
   
       3 . The control valve of  claim 1 , wherein said body and said control chamber intersect at a neck portion, and wherein said collar clamps against an internal surface of said neck portion. 
   
   
       4 . The control valve of  claim 3 , wherein said neck portion features a circumferential groove, and wherein said collar is provided with a circumferential locking element circumscribing a majority of said collar and a tightening arrangement, said tightening arrangement being configured for displacing said circumferential locking element outwards into said groove so as to clamp said collar against said internal surface of said neck portion. 
   
   
       5 . The control valve of  claim 4 , wherein said tightening arrangement includes a plurality of bolts deployed within substantially radial threaded bores spaced around said collar. 
   
   
       6 . The control valve of  claim 4 , wherein said circumferential groove includes an inclined clamping surface deployed such that outward displacement of said locking element against said inclined clamping surface displaces said guide-and-seat insert towards said opening so as to clamp said seat against said opening. 
   
   
       7 . The control valve of  claim 1 , wherein said plug includes a replaceable peripheral strip for contacting said plug guides. 
   
   
       8 . The control valve of  claim 1 , wherein said body is formed from a first material and wherein said guide-and-seat insert is formed from a second material having a higher wear-resistance than said first material. 
   
   
       9 . The control valve of  claim 8 , wherein said plug includes a replaceable peripheral strip for contacting said plug guides, and wherein said replaceable peripheral strip is formed from a material having a lower wear-resistance than said second material. 
   
   
       10 . The control valve of  claim 1 , wherein said plug has a central axis parallel to a direction of movement of said actuator, and wherein a direction from a center of said opening towards a center of said outlet defines a primary flow vector, all of said plurality of plug guides being angularly spaced from said primary flow vector by at least 20 degrees. 
   
   
       11 . The control valve of  claim 10 , wherein two of said plurality of plug guides are located symmetrically at a given angular spacing on each side of said primary flow vector. 
   
   
       12 . The control valve of  claim 1 , wherein said given angular spacing is between about 40 and about 50 degrees. 
   
   
       13 . The control valve of  claim 1 , wherein said plurality of plug guides are deployed such that, both under forward flow conditions from said inlet to said outlet and under reverse flow conditions from said outlet to said inlet, drag forces acting on said plug are opposed by three-point support of said plug by said linear bearing and two of said plug guides. 
   
   
       14 . The control valve of  claim 1 , wherein said actuator includes a flexible diaphragm deployed so as to subdivide an internal volume of said control chamber. 
   
   
       15 . The control valve of  claim 1 , further comprising a supplementary actuator located outside said control chamber and mechanically linked to said plug. 
   
   
       16 . The control valve of  claim 1 , further comprising a linear bearing deployed between said plug and said actuator such that, when said actuator moves towards said withdrawn position, said plug is free to move between an open position in which fluid flows from said inlet to said outlet and a closed position in which said plug closes against said closure surface of said valve seat so as to block the passage of fluid from said outlet to said inlet, thereby operating as a check valve. 
   
   
       17 . A control valve for regulating flow of fluids comprising:
 (a) a body having an inlet, an outlet and a passageway through which the fluid passes from said inlet to said outlet, said passageway passing through an opening;   (b) an actuator located in a control chamber connected to said body and configured to move along an axis through a range of motion from a retracted position to an extended position;   (c) a plug associated with said actuator such that movement of said actuator from said retracted position towards said extended position displaces said plug towards said opening; and   (d) a guide-and-seat insert including:
 (i) a valve seat configured to seal against said opening and to provide a closure surface against which said plug closes, 
 (ii) a plurality of plug guides integrally formed with said valve seat and extending from said seat towards said control chamber, and 
 (iii) a collar attached to or integrally formed with said plurality of plug guides and configured for clamping against an internal surface of said control valve so as to clamp said valve seat against said opening, 
   such that, when said plug is displaced by said actuator, said plug moves in sliding engagement with at least two of said plug guides, and such that, when said actuator moves to said extended position, said plug closes against said closure surface of said valve seat so as to block the passage of fluid from said inlet to said outlet,   and wherein said plug is configured as an unbalanced plug free to move, when said actuator is displaced towards said retracted position, between an open position and a closed position, thereby functioning as a check valve.