Overfill preventing valve

• US 5,842,500 A
• Filed: 08/04/1997
• Issued: 12/01/1998
• Est. Priority Date: 08/04/1997
• Status: Expired due to Term

• Current Assignee: Marshall Excelsior Co.
• Original Assignee: Harsco Technologies Corporation (Harsco Corporation)
• Inventors: Nitchke, David Earl, Smith, Paul Joseph, Hawkes, Steven Francis, Janak, John Michael, Rockwood, James Michael
• Primary Examiner(s): Walton, George L.
• Application Number:
  US08/905,419
• Time in Patent Office: 484 Days
• Field of Search: 137/412, 137/413, 137/416, 137/430, 137/433, 137/614.2, 141/198, 251/44
• US Class Current: 137/413
• CPC Class Codes: F16K 1/302 with valve member and actuator on the same side of the seat
• CPC Class Codes: F16K 1/307 Additional means used in combination with the main valve
• CPC Class Codes: F17C 2250/0413 with floats
• CPC Class Codes: Y10T 137/7371 Fluid pressure
• CPC Class Codes: Y10T 137/7378 From tank
• CPC Class Codes: Y10T 137/7436 Float rigid with valve
• CPC Class Codes: Y10T 137/88054 Direct response normally closed valve limits direction of flow

Abstract

An overfill preventing valve (20) is adapted to be operatively interposed in a flow path between a fluid source (21) and a compressed fluid storage cylinder (22) to prevent the cylinder from being overly filled. The improved valve includes an elongated tubular body having a first seat (25), a first space (26), a second space (28), a second seat (29), a third space (30), a third seat (31), a fourth space 37 and an entrance portion (32) communicating with a source. A passageway (33) continuously communicates the first and fourth spaces. The second and fourth spaces communicate with the interior of the cylinder. A float (36) is contained within the body for movement toward and away from the first seat in response to the liquid level in the cylinder. A valve member (38) is mounted on the body for sealed movement toward and away from the second seat. This valve member separates the first space from the second space. The valve member is biased to move away from the second seat. A piston (40), separating the third space from the fourth space, is mounted for sealed sliding movement therealong toward and away from the third seat. The piston is biased to move toward the third seat. The piston has a variable-area orifice communicating the entrance portion with the third space. The cross-sectional area of this orifice varies as a function of the direction of the flow. When it is desired to fill the cylinder and the float does not engage the first seat, incoming fluid displaces the piston away from the third seat and flows from the entrance portion into the cylinder via the fourth space. However, when the float sealingly engages the first seat, the valve member is caused to sealingly engage the second seat, and the piston is caused to sealingly engage the third seat to prevent further incoming flow from the source to the cylinder.

Claims

1. A valve adapted to be operatively interposed in a flow path between a fluid source and a fluid storage tank to prevent said tank from being overly filled, comprising:

an elongated tubular body sequentially including a first seat, a first space, a second space, a second seat, a third space, a third seat, a fourth space and an entrance portion communicating with said source, and further including a passageway communicating said first space with said fourth space, and wherein said second and fourth spaces communicate with an interior of said tank;

a float mounted on said body for movement toward and away from said first seat in response to a level of liquid within said tank, said float being adapted to sealingly engage said first seat when said tank is upright and said liquid level rises above a predetermined level, whereupon said communication between said first space and said interior of said tank is substantially shut off by said sealing engagement of said float with said first seat;

a member mounted in said body for movement relative thereto toward and away from said second seat, said member separating said first space from said second space, said member being biased to move away from said second seat and responsive to a pressure differential between said first and second spaces; and

a piston mounted on said body and separating said third and fourth spaces for sealed movement therealong toward and away from said third seat, said piston being biased to move toward said third seat, said piston having an orifice communicating said entrance portion with said third space;

whereby when it is desired to fill said tank and said float does not engage said first seat, incoming fluid may displace said piston away from said third seat and flow from said entrance portion into said tank via said fourth space, but when said float sealingly engages said first seat, continued incoming flow from said fluid source through said fourth space causes pressure in said first space to be reduced via said passageway communicating therebetween, thereby creating said pressure differential between said first space and said second space sufficient to overcome said bias of said member, wherein said member is caused to sealingly engage said second seat and said piston is caused to sealingly engage said third seat to prevent further incoming flow from said source to said tank.

2. A valve as set forth in claim 1 and further comprising a cage mounted on said body for confining said float to move toward and away from said first seat.

3. A valve as set forth in claim 1 wherein fluid flowing through said passageway becomes entrained with incoming fluid flowing between said piston and said third seat.

4. A valve as set forth in claim 1 wherein said second seat faces toward the direction of incoming fluid flow.

5. A valve as set forth in claim 1 wherein said third seat faces away from the direction of incoming fluid flow.

6. A valve as set forth in claim 1 wherein the area of said orifice varies as a function of the direction of flow between said piston and third seat.

7. A valve as set forth in claim 6 and further comprising a poppet mounted for movement relative to said piston for varying the area of said orifice.

8. A valve as set forth in claim 1 and further comprising a resilient valve mounted on said piston for varying the area of said orifice.

9. A valve as set forth in claim 1 and further comprising a relief valve operatively arranged to relieve excess pressure within said third space and said entrance portion to said tank.