Electric Motor Actuated Stop and Self-Closing Check Valve
An electric motor actuated stop/check valve for industrial use such as liquid pumping systems which has a controlled opening and closing rate when liquid flow is in a forward direction but closes quickly upon reverse flow of liquid with no action from the electric motor actuator. Actuation of the valve is by an electric motor which provides movement to an actuator rod which contacts the disc stem. The disc stem and the actuator rod are not connected which allows the valve disc and disc stem free movement. No action by the electric motor is required. A spring biasing the valve disc toward the closed position and a hydraulically operated valve closing-speed regulator reduces or eliminates slamming of the valve disc against the valve seat. In a preferred method of operation liquid surge pressure transients are reduced or eliminated and slamming of valve components is prevented.
This application is a Continuation of U.S. application Ser. No. 11/117,637, filed Apr. 28, 2005, which is a Continuation of U.S. application Ser. No. 10/942,062, filed Sep. 15, 2004, which is a Continuation-in-Part of application Ser. No. 10/617,435, filed Jul. 11, 2003, which is a Continuation-in-Part of application Ser. No. 09/507,273, filed Feb. 18, 2000. The contents of application Ser. No. 09/507,273 are hereby incorporated by reference.
BACKGROUND OF THE INVENTION1. Field of the Invention
This invention relates to electric motor actuated valves incorporating a check valve feature for controlling the flow of pumped liquids in applications such as are associated with municipal water supply or sewage treatment facilities and industry.
2. Description of Related Art
Valves for controlling liquid flow and preventing its back-flow are known in the art and are commonly referred to as stop/check valves. Such valves can be actuated to control liquid flow by manual, hydraulic and other means.
U.S. Pat. No. 4,667,696 describes a stop/check valve which utilizes a ball which closes upon a valve seat to prevent liquid flow in a back-flow direction. Flow in a desired direction is regulated by a hand-cranked closing device acting on the ball.
U.K. Patent specification 141,148 describes a stop/check valve for fluid having a pressure plate extending from a clack into a path of return flow of the fluid so as to urge the clack to a closed position. In an embodiment having control of forward-flow, a hand-actuated spindle is used to position the clack.
U.S. Pat. No. 4,945,941 describes a stop/check valve having a feature facilitating movement of a valve disc to a closed position with back-flow of liquid by use of a ridge on the valve seat and a deflector ring on the valve disc to deflect the flow of the fluid. Control of the liquid for forward-flow is carried out with a hand-actuated valve stem.
SUMMARY OF THE INVENTIONThe present invention provides an electric motor actuated valve to control liquid flow in a forward direction, prevent flow of the liquid in a reverse direction and carry out such control while eliminating or reducing liquid surge pressure transients and slamming of components within the valve. A discontinuous connection between a motor actuation component and valve seating components allows valve seating solely by means of liquid acting on the valve seating components to close the valve and prevent liquid back-flow. Such back-flow prevention occurs without action by the electric motor.
Disc stem 28 extends through a valve body cover 36 which in the preferred embodiment is provided with a bronze bushing 38 to enable substantially free movement of valve disc 26 and disc stem 28 along longitudinal axis 40 of the disc stem.
The valve of the invention is used in-line to 1) stop flow in the forward direction, 2) control flow in the forward direction (from full flow to a restricted flow) and 3) prevent back-flow (flow in a direction opposite to forward-flow). In the preferred embodiment valve body 12 and valve seat 24 are dimensioned such that the net flow area is no less than the cross-sectional area of the piping to the inlet and outlet ports so as to minimize flow restriction by the valve. That is the liquid does not encounter a cross-section, perpendicular to the direction of flow, which is of less area than the cross-sectional area of the adjacent piping. Configuration of the valve body, valve seat and valve disc is such that dead or non-flow cavities do not exist within the valve body and the valve is therefore said to be “self-cleaning”.
Operatively attached to valve body 12 is electric motor actuator 41 having actuator rod 42 positioned to act on valve stem 28. Actuator rod 42 is preferably attached to a threaded shaft 43 which rotates through action of the electric motor to move it linearly along axis 40. In event of loss of power or inoperability of the motor the threaded shaft can be actuated manually with a hand-crank 46. Actuator rod 42 is prevented from rotating with the threaded shaft by an extension from the side of the actuator rod which extends into a slot in anti-rotation sleeve 47. Gears linking electric motor 44 and hand-crank 46 to the threaded shaft are within housing 48. A closed position of the valve as depicted in
As described above, the electric motor actuated stop and self-closing check valve of the invention can be used in municipal water supply systems or sewage treatment systems as a pump control and stop check valve although it is not limited to such usage. In normal operation liquid flow is in the direction indicated by arrows 18 with such flow provided by action of at least one pump upstream of the valve. In event of pump shutdown, either intended or by a power failure, back-flow of the liquid can occur when a valve to check such flow is not provided. Such back-flow is usually undesirable and is prevented by the valve of the invention without any action by the electric motor. Such feature is of importance when back-flow is caused by a power failure and power is not available to the electric motor.
In
A common problem with many check valves when a reversal of liquid flow direction occurs is “slamming” of the valve disc against the valve seat. Such slamming is greatly reduced in the valve of this invention by use of a compression spring 52 which biases the valve disc and its stem toward the closed position. Selection of spring characteristics is dependent on pressure of the liquid being pumped against valve disc face 50. The spring is selected to be strong enough to assist in closing the valve when flow in the forward direction stops so that the valve is at least partially closed when the back-flowing liquid applies pressure to valve disc back face 51 and any slamming of the valve disc is reduced or eliminated because of the shortened distance it moves. The spring can not be so strong as to restrict flow in the forward direction in a significant amount. Spring 52 is shown in a partially compressed state in
During loss of power, when liquid flow is no longer in the direction of arrows 56 and back-flow is beginning in the direction of arrow 78 (
Although elbow valve 88 with solely spring means 105 for reducing or eliminating valve disc slamming is shown, such elbow valve can be provided with hydraulic closing speed regulating means as shown and described for wye valve 10 (
A preferred method of operating a liquid pumping system utilizing a valve of the invention is schematically shown in
During normal pumping operation of the pumping system with flow of liquid in the direction of arrow 113, and actuator rod 42 in the retracted position (
While specific materials and configurations have been set forth for purposes of describing embodiments of the invention, various modifications can be resorted to, in light of the above teachings, without departing from applicants' novel contributions; therefore in determining the scope of the present invention reference shall be made to the appended claims.
Claims
1-19. (canceled)
20. An electric motor actuated stop and self-closing check valve, comprising:
- a valve body having an inlet port and an outlet port;
- a valve seat intermediate the inlet port and the outlet port;
- a valve disc having a disc stein, the valve disc being moveable toward and away from the valve seat along a direction of a longitudinal axis of the disc stem;
- an electric motor with an actuator rod moveable by action of the electric motor, the actuator rod having an extended position whereat the valve disc is moved to sealingly engage with the valve seat and a retracted position whereat the valve disc is free to move toward and away from the valve seat according to a flow of a fluid through the valve body; and
- a spring configured for providing a bias to the valve disc toward the valve seat.
21. The electric motor actuated stop and self-closing check valve according to claim 20, wherein the spring is positioned between the valve stem and the electric motor.
22. The electric motor actuated stop and self-closing check valve according to claim 20, wherein the valve disc is removably secured to the valve stem.
23. The electric motor actuated stop and self-closing check valve according to claim 20, wherein the valve body includes an opening configured to allow insertion and removal of the valve disc.
24. The electric motor actuated stop and self-closing check valve according to claim 23, further comprising a valve body cover covering the valve body opening.
25. The electric motor actuated stop and self-closing check valve according to claim 24, wherein the disc stem at least partially extends through the valve body cover.
26. The electric motor actuated stop and self-closing check valve according to claim 25, wherein the electric motor is disposed outside of the covered valve body.
27. The electric motor actuated stop and self-closing check valve according to claim 26, wherein the electric motor is attached to the valve body cover.
28. A method of controlling a flow of a fluid through a valve, comprising:
- providing an electric motor actuated stop and self-closing check valve installed to function as a pump control and stop check valve, comprising: a valve body having an inlet port and an outlet port; a valve seat intermediate the inlet port and the outlet port; a valve disc having a disc stem, the valve disc being moveable toward and away from the valve seat along a direction of a longitudinal axis of the disc stem; an electric motor with an actuator rod moveable by action of the electric motor, the actuator rod having an extended position whereat the valve disc is moved to sealingly engage with the valve seat and a retracted position whereat the valve disc is free to move toward and away from the valve seat according to a flow of a fluid through the valve body; and a spring configured for providing a bias to the valve disc toward the valve seat; and
- coordinating the operation of the valve and a pump to start the pump and extend and retract the actuator rod using the electric motor to avoid liquid surge pressure transients and slamming of check valve components during pumping start-up and termination.
29. The electric motor actuated stop and self-closing check valve according to claim 20, further comprising a hydraulically operated valve disc closing-speed regulator operatively attached to the valve to control the closing speed of the valve disc;
- wherein said closing-speed regulator comprises: a cylinder operatively attached to the valve body, a piston operatively attached to the disc stem for movement within said cylinder along its longitudinal axis, and a hydraulic oil reservoir with connecting piping to the cylinder, said connecting piping having a solenoid valve and a flow regulating valve, said solenoid valve and said flow regulating valve being piped in parallel arrangement.
30. The electric motor actuated stop and self-closing check valve according to claim 29, wherein said flow regulating valve is a check valve.
31. The method of controlling a flow of a fluid through a valve according to claim 28, further comprising a hydraulically operated valve disc closing-speed regulator operatively attached to the valve to control the closing speed of the valve disc;
- wherein said closing-speed regulator comprises: a cylinder operatively attached to the valve body, a piston operatively attached to the disc stein for movement within said cylinder along its longitudinal axis, and a hydraulic oil reservoir with connecting piping to the cylinder, said connecting piping having a solenoid valve and a flow regulating valve, said solenoid valve and said flow regulating valve being piped in parallel arrangement.
32. The method of controlling a flow of a fluid through a valve according to claim 31, wherein said flow regulating valve is a check valve.
Type: Application
Filed: May 17, 2013
Publication Date: Nov 28, 2013
Inventors: Donald L. Bartell, JR. (Beaver Falls, PA), Joseph E. Lescovich (Pittsburgh, PA), William J. Nicholl (Pittsburgh, PA)
Application Number: 13/896,703
International Classification: E03B 5/00 (20060101);