Gate valve with position indicator

• US 4,406,303 A
• Filed: 08/04/1981
• Issued: 09/27/1983
• Est. Priority Date: 08/04/1981
• Status: Expired due to Fees

• Current Assignee: Joy Manufacturing Company
• Original Assignee: ACF Industries Holding Corporation (Icahn Associates Holding LLC)
• Inventors: Kilmoyer, James E.
• Primary Examiner(s): Cohan, Alan
• Assistant Examiner(s): Rivell, John A.
• Application Number:
  US06/289,932
• Time in Patent Office: 784 Days
• Field of Search: 137/552, 137/554, 137/556, 137/559, 116/277
• US Class Current: 137/554
• CPC Class Codes: F16K 37/0008 Mechanical means F16K37/0075 takes precedence
• CPC Class Codes: H03K 17/945 Proximity switches H03K17/96 takes precedence
• CPC Class Codes: Y10T 137/8175 Plural
• CPC Class Codes: Y10T 137/8242 Electrical
• CPC Class Codes: Y10T 137/8359 Inspection means

Abstract

The invention relates to a gate valve (10) having both visual and electrical position indicating means for signalling when the valve is in the fully open and fully closed conditions. A position indicator housing (50) on the valve body (11) receives and accommodates therein a longitudinal valve stem extension (33) of the gate element (15) as the gate element moves between the open and closed positions. The indicator housing (50) is filled with transparent oil and sealed off from fluid communication with the valve chamber (12) and a diaphragm (135) in the wall of the indicator housing accommodates movement of the gate extension (33) inwardly and outwardly of the indicator housing (50) and is exposed to the fluid environments internal and external of said housing to avoid pressure differentials across the housing wall. A pair of proximity sensors (100, 104) with sensing elements (101, 106) of the electrical impedance type are mounted in the indicator housing (50) adjacent the valve stem extension (33) of the gate element at locations corresponding to the extremities of travel of the gate (15) and extension (33) thereof. The sensors energize associated electrical circuit means (FIG. 6) to signal to a remote monitoring facility (M) when the valve (10) is in the fully open or fully closed position. In addition, a pair of viewports (W) are provided in opposed locations of the indicator housing (50), particularly for subsea applications, to permit visual assessment of valve element position.

Claims

1. A valve for subsea applications, said valve having a valve body defining a valve chamber and having inlet and outlet flow passages in fluid communication with the valve chamber, a valve element within said valve chamber and being movable between open and closed positions thereof for controlling the flow of fluid through said flow passages;

means for imparting movement to said valve element between said open and closed positions;

a valve position indicator housing attached to said valve body, said housing being filled with a transparent oil or other electrically non-conductive, non-corrosive liquid;

an extension member secured to said valve element and extending from said valve element into said indicator housing, said extension member being movable within said indicator housing between a first position wherein said valve element closes said valve and a second position wherein said valve element opens said valve;

means for sealing off said indicator housing from fluid communication with said valve chamber;

a diaphragm means comprising a diaphragm installed in the wall of said indicator housing in a position exposed to the fluid within said indicator housing and the fluid pressure external of said housing to thereby avoid pressure differentials across said housing, said diaphragm means being responsive to the movement of said valve element extension member inwardly and outwardly of said indicator housing to accommodate volume changes induced in said indicator housing by said extension member;

circuit means for transmitting valve position signals to signal receiving apparatus when said valve element is in said closed and open positions, said circuit means comprising a first electrical impedance element fixed in said indicator housing at a location adjacent said extension member corresponding to a first extremity of movement of said valve element and extension member when said valve element closes said valve, and a second electrical impedance element fixed in said indicator housing at a location adjacent said extension member and corresponding to the second extremity of movement of said valve element and extension member when said valve element opens said valve, with the spacing between said first and second electrical impedance elements corresponding substantially to the extent of travel of said extension member between said first and second positions;

a metallic appendage affixed to said extension member and disposed along the path between said first and second electrical impedance elements whereby movement of said valve element to the open or closed positions causes said appendage to move in contact or in proximity to one of said electrical impedance elements as to affect the electrical impedance thereof;

said circuit means being responsive to impedance changes induced in said first and second impedance elements by proximity to or in contact with said appendage on said extension member when in said first and second positions for producing electrical output signals indicating when said valve element is in the closed and open positions.

2. A valve as set forth in claim 1 further including transparent window means provided in said indicator housing whereby the actual position of said valve element can be readily determined by visual observation through said window means.

3. A valve as set forth in claim 2 wherein said window means comprises a pair of transparent viewports provided at opposed locations in said indicator housing.