Backflow preventor

• US 20060185731A1
• Filed: 01/19/2006
• Published: 08/24/2006
• Est. Priority Date: 01/21/2005
• Status: Active Grant

• Current Assignee: ZURN Water LLC (Zurn Elkay Water Solutions Corp.)
• Original Assignee: Zurn Industries Incorporated (Rexnord Corporation)
• Inventors: Orr, William M., Grable, Jonathan L.
• Granted Patent: US 7,784,483 B2
• Time in Patent Office: Days
• US Class Current: 137/115.130
• CPC Class Codes: E03B 7/077 Arrangement of backflow preventing devices
• CPC Class Codes: E03C 1/106 using two or more check valves
• CPC Class Codes: E03C 1/108 having an aerating valve
• CPC Class Codes: F16K 11/105 Three-way check or safety valves with two or more closure members
• CPC Class Codes: Y10T 137/2605 Pressure responsive
• CPC Class Codes: Y10T 137/6086 Assembling or disassembling check valve
• CPC Class Codes: Y10T 137/7838 Plural

Abstract

A backflow preventor that generally includes a modular fluid arrangement having a modular strut, a one-piece modular cage, a relief valve fluidly connected to the modular cage, and at least one in-line check valve removably housed in the modular cage. In operation, when backflow occurs, pressure in a chamber of the relief valve increases to provide a passageway for fluid to flow out of the modular cage, through the relief valve, to the environment. When the backflow stops, the pressure in the chamber decreases and the passageway closes, moving the fluid through the interior of the modular cage.

Claims

1. A modular fluid arrangement comprising:

a modular strut having an inlet body and an outlet body and defining a modular cage receiving area therebetween; and

a modular cage removably secured to said modular strut and received by the modular cage receiving area, said modular cage having a first open end and a second open end and defining an interior cavity, wherein the interior cavity of said modular cage is in fluid communication with said inlet body and said outlet body of said modular strut, and wherein the interior cavity of said modular cage is adapted to receive at least one check valve.

2. The modular fluid arrangement of claim 1, further comprising at least one check valve in the interior cavity of the modular cage.

3. The modular fluid arrangement of claim 1, wherein the modular cage and the modular cage receiving area are sized relative to one another, such that the modular cage and the modular strut can move relative to one another in a longitudinal direction.

4. The modular fluid arrangement of claim 1, wherein an outer surface portion of the modular cage has a wedge surface adjacent at least one of the first and second open ends to seat the modular cage in the modular cage receiving area of the modular strut.

5. The modular fluid arrangement of claim 1, further comprising a pressure relief valve securely mounted to the exterior of the modular cage, the pressure relief valve having a valve arrangement having a first position and a second position, wherein in the first position, the valve arrangement provides fluid communication between the interior of the modular cage and exterior of the modular cage, and in the second position prevents fluid communication between the interior of the modular cage and exterior of the modular cage.

6. The modular fluid arrangement of claim 5, wherein the pressure relief valve comprises a first interior chamber and a second interior chamber separated by a diaphragm and a passageway extending from the first chamber of the pressure relief valve to exterior of the pressure relief valve and the exterior of the modular cage, wherein with the valve arrangement in the first position, fluid communication is provided between the first chamber of the pressure relief valve and the passageway, and the modular cage further comprising a valve tap providing fluid communication between the interior of the modular cage and the first chamber of the pressure relief valve.

7. The modular fluid arrangement of claim 6, further comprising at least one check valve in the interior cavity of the modular cage.

8. The modular fluid arrangement of claim 6, wherein the modular cage further comprises a first port in fluid communication with the interior of the modular cage and the second interior chamber of the pressure relief valve.

9. The modular fluid arrangement of claim 6, wherein the valve arrangement comprises the diaphragm having a first surface facing the first chamber and an opposite second surface facing the second chamber, with a hole interconnecting the first and second surfaces, a piston having a closed end and an open end, with the open end facing the second surface of the diaphragm, a spring in the piston housing, a valve guide having at least one prong mounted in the piston against the biasing action of the spring, and a valve seat having at least one hole secured in the open end of the piston to capture the diaphragm between the piston and the valve seat, with the at least one prong of the valve guide extending through the at least one hole of valve seat, and wherein with the valve arrangement in the first position, the diaphragm is biased away from the modular cage and distance between the valve seat and the exterior of the modular cage increases to provide fluid communication between the first chamber and the passageway, and, with the valve arrangement in the second position biasing action on the diaphragm is removed.

10. The modular fluid arrangement of claim 9, wherein with the fluid arrangement in the first position, a fluid passageway is provided from the interior of the modular cage, through the valve tap, into the first chamber, through the valve seat and valve guide, through the spring, and out of the pressure relief valve through the passageway.

11. The modular fluid arrangement of claim 10, wherein the valve tap further comprises a seal mounted in a groove provided in the outer surface of the modular cage and a seal retained to secure the seal in position, wherein with the valve arrangement in the second position, the spring guide engages a portion of the seal.

12. The modular fluid arrangement of claim 6, wherein the switch arrangement comprises the diaphragm having a first surface facing the first chamber and an opposite second surface facing the second chamber, with a hole interconnecting the first and second surfaces, a piston having a closed end and an open end, with the open end facing the second surface of the diaphragm, a spring in the piston housing, and a valve seat having at least one hole secured in the open end of the piston to capture the diaphragm between the piston and the valve seat, and wherein with the valve arrangement in the first position, the diaphragm is biased away from the modular cage and distance between the valve seat and the exterior of the modular cage increases to provide fluid communication between the first chamber and the passageway, and with the valve arrangement in the second position, biasing action on the diaphragm is removed.

13. The modular fluid arrangement of claim 12, wherein with the fluid arrangement in the first position, a fluid passageway is provided from the interior of the modular cage, through the valve tap, into the first chamber, through the valve seat, over the spring, and out of the pressure relief valve through the passageway.

14. The modular fluid arrangement of claim 13, wherein the valve tap further comprises a seal mounted in a groove provided in the outer surface of the modular cage and a seal retainer to secure the seal in position, the seal retainer having at least one prong extending away from the modular cage, and the valve seat having at least one hole, and wherein with the valve arrangement in the second position, the spring guide passes over the retainer and engages a portion of the seal.

15. The modular fluid arrangement of claim 14, wherein the modular cage further comprises at least one tap extending from the modular cage and in fluid communication with the interior of the modular cage.

16. A method of installing, repairing, and operating a modular fluid arrangement, wherein the method includes the practice of at least one of the following groups of steps:

Group A comprising the steps of;

inserting at least one check valve into interior cavity of a modular cage;

removably securing the modular cage into receiving area of a modular strut; and

connecting a first open end of the modular cage with the inlet body of the modular strut, and a second open end of the modular cage with the outlet body of the modular strut;

Group B comprising the steps of;

closing the inlet valve and outlet valve of the modular strut;

removing the modular cage from the modular strut;

removing one end of the modular strut;

removing unacceptable check valve from the interior of the modular cage;

inserting acceptable check valve into the interior of the modular cage;

removably securing the modular cage into the receiving area of the modular strut; and

connecting a first open end of the modular cage with the inlet body of the modular strut, and a second open end of the modular cage with the outlet body of the modular strut; and

Group C comprising the steps of;

moving a fluid through the inlet end of the strut, the first open end of the modular cage, through the modular cage to the second outlet of the modular cage through the second outlet of the strut;

directing a portion of the fluid moving through the first end of the modular cage to a first chamber of a relief valve and another portion of the fluid into a second chamber of the relief valve;

collecting fluid that moves from the second end of the strut and the second end of the modular cage in the interior of the modular cage;

directing fluid in the modular cage to the first chamber until the pressure exceeds a predetermined pressure, at which time the fluid moves from the interior of the modular cage into the first chamber and out of the first chamber into the environment, exterior of the modular cage and the relief valve.

17. The method of claim 16, wherein the method includes the practice of Group C and the first and second chambers are separated by a diaphragm and, during the practice of the directing fluid step, the pressure in the first chamber is sufficient to increase the first chamber and decrease the second chamber, opening a valve arrangement to move fluid out of the first chamber.