Composite action type water-hammer-preventive check valve

• US 5,769,116 A
• Filed: 09/13/1996
• Issued: 06/23/1998
• Est. Priority Date: 01/31/1994
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Yokota Seisakusho
• Original Assignee: Hiroshi Yokota, Kabushiki Kaisha Yokota Seisakusho, Shingo Yokota
• Inventors: Yokota, Hiroshi, Yokota, Shingo
• Primary Examiner(s): Ferensic, Denise L.
• Assistant Examiner(s): Kim, Joanne Y.
• Application Number:
  US08/682,734
• Time in Patent Office: 648 Days
• Field of Search: 137/527.4, 137/527, 137/514, 251/87, 251/84
• US Class Current: 137/514
• CPC Class Codes: E03C 1/104 using a single check valve
• CPC Class Codes: F16K 1/2007 specially adapted operating means therefor operating means per se F16K31/00
• CPC Class Codes: F16K 15/03 with a hinged closure member or with a pivoted closure member
• CPC Class Codes: F16K 15/033 spring-loaded
• CPC Class Codes: F16K 15/1821 for check valves with a hinged or pivoted closure member
• CPC Class Codes: F16K 47/00 Means in valves for absorbing fluid energy for pipes F16L55/00
• CPC Class Codes: F16K 47/0111 the valve members comprising a plunger sliding within a fixed dashpot
• CPC Class Codes: F16K 47/023 for preventing water-hammer, e.g. damping of the valve movement
• CPC Class Codes: F16L 55/055 Valves therefor
• CPC Class Codes: Y10T 137/785 With retarder or dashpot
• CPC Class Codes: Y10T 137/7898 Pivoted valves
• CPC Class Codes: Y10T 137/7901 Valve head movably connected for accommodation to seat

Abstract

The invention has its object to radically resolve an untapped technical issue in a non-water hammering check valve device, in which a valve disc, a valve seat and a surrounding flow passage are configured such that the valve disc is substantially seated on the valve seat at the time when input to a pump is shut off and a discharge flow in the flow passage loses inertia to stop, and to provide a reasonable non-water hammering check valve device of a simple and clear construction which suffers a small resistance loss of a valve at the time of a predetermined maximum flow rate, can readily accommodate an abrupt change in a flow state without delay in valve closing operation and provides a uniform and close seating on the valve seat at the time of valve seating to prevent water hammering. In the non-water hammering check valve device, a valve disc (4) is connected to an arm portion (5) through a valve disc support shaft (6) with a required freedom of swinging, and the arm portion (5) is connected to a valve body (1) through an arm support shaft (7). At the time of valve opening, the valve disc (4) is caused by an additional acting force, which turns the valve disc (4) about the valve disc support shaft (6), to be floatingly supported in the flow passage while an upstream end (4a) of the valve disc and an upstream end (5a) of the arm portion preferentially abut against each other all the time. At the time of valve closing, a downstream end (4b) of the valve disc preferentially abuts against a valve seat (3), and in a subsequent valve seating stroke, the entire surface of the valve disc (4) comes into uniform and close contact with the valve seat (3) to prevent water hammering caused by counterflow.

Claims

1. A composite action type water-hammer-preventive check valve, comprising:

a valve casing having therein a flow passage with a flow line along which a fluid flows;

a valve seat disposed across said flow line in an inclined attitude relative to the flow line so that the valve seat has an upstream lateral side positioned upstream of a downstream lateral side with respect to said flow line;

an arm member in said valve casing at a position downstream from said valve seat and pivotably connected to said valve casing by an arm member support shaft positioned adjacent to said upstream lateral side of the valve seat, said arm member having an upstream end portion adjacent to said upstream lateral side of the valve seat and a downstream end portion;

a valve element shaped to provide small flow resistance and small inertial resistance and pivotably connected to said arm member by a valve element support shaft, said valve element being positioned to face said valve seat at a downstream side thereof and being movable between a fully open position away from the valve seat and a fully closed position in which the valve element is in close contact with said valve seat, said valve element having an upstream end portion for contacting said upstream lateral side of the valve seat, and a downstream end portion for contacting said downstream lateral side of the valve seat, said valve element being disposed to be gravitationally urged in a valve closing direction;

said valve element being urged to turn around said valve element support shaft so that said upstream end portion of the valve element is caused to contact said upstream end portions of the arm member; and

a valve closing member connected between said valve casing and one of said arm member and said valve element to urge said arm member and said valve element in said valve closing direction, said valve closing member being provided at such a position as to provide a minimum value of valve closing force in said valve fully open position of the valve and a maximum value of valve closing force in said valve closing position;

whereby when fluid flow along said flow line through said passage stops, due to cessation of inertia after power supply to a pump is stopped, the valve element will be seated on the valve seat with said downstream end portion of the valve element first contacting the valve seat and with said upstream end portion of the valve element thereafter contacting the valve seat.

2. The composite action type water-hammer-preventive check valve according to claim 1, wherein said valve closing force in a valve fully open position is adjusted to balance a valve opening force exerted by the fluid flow.

3. The composite action type water-hammer-preventive check valve according to claim 1, wherein said valve closing member is a spring.

4. The composite action type water-hammer-preventive check valve according to claim 1, wherein said flow passage extends substantially horizontally.

5. The composite action type water-hammer-preventive check valve according claim 1, further comprising:

a braking device for braking said valve element during movement of the valve element in which the downstream end portion of the valve element is caused to contact the valve seat and thereafter the upstream end portion of the valve element is caused to contact the valve seat.

6. A composite action type water-hammer-preventive check valve, comprising:

a valve casing having therein a flow passage with a flow line along which a fluid flows.

a valve seat disposed across said flow line at an inclined attitude relative to the flow line so that the valve seat has an upstream lateral side positioned upstream of a downstream lateral side with respect to said flow line;

an arm member in said valve casing at a position downstream from said valve seat and pivotably connected to said valve casing by an arm member support shaft positioned adjacent to said upstream lateral side of the valve seat, said arm member having an upstream end portion adjacent to said upstream lateral side of the valve seat and a downstream end portion;

a valve element pivotably connected to said arm member by a valve element support shaft to face said valve seat at a downstream side thereof to be movable between a fully open position away from the valve seat and a fully closed position in which the valve element is in close contact with said valve seat, said valve element having an upstream end portion for contacting said upstream lateral side of the valve seat, and a downstream end portion for contacting said downstream lateral side of the valve seat, said valve element being disposed to be gravitationally urged in a valve closing direction;

said valve element being urged to turn around said valve element support shaft so that said upstream end portion of the valve element is caused to contact said upstream end portion of the arm member; and

a braking device for braking said valve element;

whereby when a fluid flow along said flow line through said passage stops due to cessation of inertia after power supply to a pump is stopped, the valve element will be seated on the valve seat with said downstream end portion of the valve element first contacting the valve seat, and with said upstream end portion of the valve element thereafter contacting the valve seat;

said braking device being operative to brake said valve element during movement of the valve element in which the downstream end portion of the valve element is caused to contact the valve seat and the upstream end portion of the valve element is thereafter caused to contact the valve seat.

7. The composite actin type water-hammer-preventive check valve according to claim 6, wherein said braking device is connected to act on said arm member.

8. The composite action type water-hammer-preventive check valve according to claim 6, wherein said braking device is disposed outside the valve casing to act on said arm member support shaft which extends outside of said valve casing.

9. The composite action type water-hammer-preventive check valve according to claim 6, wherein said braking device is connected to act between said valve element and said arm member.

10. The composite action type-water-preventive check valve according to claim 6, wherein said braking device is connected to act between said valve element and said valve seat.