The present application relates to fluid valves, and particularly a check valve for a backflow preventer.
Check valves traditionally allow flow in one direction while preventing reverse flow. In some cases, a poppet (e.g., a disc) of a check valve generally remains in a fluid flow path in an open position.
In one independent aspect, a check valve is provided for a backflow preventer having a housing and a fluid flow channel therethrough. The check valve includes: a valve seat; a poppet movable between a closed position and an open position, the poppet positioned against the valve seat and inhibiting fluid flow past the valve seat while the poppet is in the closed position, the poppet spaced apart from the valve seat and permitting fluid flow past the valve seat while the poppet is in the open position; a guide portion including a first guide surface and a second guide surface; a first stem coupled to the poppet and movable along the first guide surface; a second stem coupled to the poppet and movable along the second guide surface; and a biasing member coupled between the first stem and the second stem, the biasing member configured to create an effective closing force that biases the poppet to the closed position.
In some aspects, the first guide surface is positioned along an upper portion of the guide portion, and the second guide surface is positioned along a lower portion of the guide portion.
In some aspects, the first stem includes a first roller for engaging the first guide surface and the second stem includes a second roller for engaging the second guide surface, wherein, as the poppet moves from the closed position to the open position, a biasing force exerted by the biasing member on the first stem increases as the first roller moves along the first guide surface.
In some aspects, the second guide surface includes a first portion and a second portion, wherein, as the poppet moves from the closed position to the open position, the second roller moves sequentially through the first portion of the second guide surface and then the second portion of the second guide surface, a biasing force exerted by the biasing member increasing as the second roller moves along the first portion of the second guide surface and the biasing force decreases as the second roller moves along the second portion of the second guide surface, the effective closing force being greater when the second stem engages the first portion of the second guide than when the second stem engages the second portion of the second guide.
In some aspects, the poppet includes a first elongated slot and a second elongated slot, wherein the first stem extends through and is movable within the first elongated slot and the second stem extends through and is movable within the second elongated slot.
In some aspects, the first stem includes a first roller for engaging the first guide surface and the second stem includes a second roller for engaging the second guide surface, wherein the biasing member exerts a force to bias the first roller into engagement with the first guide surface and bias the second roller into engagement with the second guide surface.
In some aspects, the lower guide track contains a stop that limits the movement of the second stem along the second guide surface.
In some aspects, the poppet is configured to be supported for pivoting movement relative to the housing of the backflow preventer, wherein when the poppet is in a fully opened position, the poppet is out of a fluid flow path.
In some aspects, the first guide surface includes a first inclined portion and the second guide surface includes a second inclined portion, the first inclined portion and the second inclined portion diverging from one another as they extend away from the seat.
In another independent aspect, a check valve is provided for a backflow preventer having a housing and a fluid flow channel therethrough. The check valve includes: a seat including a sealing edge; a poppet including a sealing portion, the poppet movable between a closed position and an open position, the sealing portion of the poppet positioned against the seat and inhibiting fluid flow past the seat while the poppet is in the closed position, the poppet spaced apart from the seat and permitting fluid flow past the seat while the poppet is in the open position; a guide portion coupled to the seat and including a first guide surface and a second guide surface; a first stem coupled to the poppet and movable along the first guide surface; a second stem coupled to the poppet and movable along the second guide surface; and a biasing member coupled between the first stem and the second stem, the biasing member exerting a biasing force to draw the first stem and the second stem toward one another, thereby biasing the sealing portion of the poppet against the sealing edge, the first guide surface and the second guide surface having a shape that transfers at least a portion of the biasing force in a direction that is normal to the sealing edge while the poppet is in the closed position.
In some aspects, the first guide surface includes a first inclined portion and the second guide surface includes a second inclined portion, the first inclined portion and the second inclined portion extending away from the seat in diverging directions.
In some aspects, the first inclined surface is positioned along an upper portion of the guide portion, and the second inclined surface is positioned along a lower portion of the guide portion.
In some aspects, the first stem includes a first roller for engaging the first inclined portion, wherein the second stem includes a second roller for engaging the second inclined portion.
In some aspects, the poppet includes a first elongated slot and a second elongated slot, wherein the first stem extends through and is movable within the first elongated slot and the second stem extends through and is movable within the second elongated slot.
In some aspects, the poppet is configured to be supported for pivoting movement relative to the housing of the backflow preventer, wherein when the poppet is in a fully opened position, the poppet is out of a fluid flow path.
In yet another independent aspect, a check valve is provided for a backflow preventer having a housing and a fluid flow channel therethrough. The check valve includes: a seat including a sealing edge; a poppet including a sealing portion, the poppet movable between a closed position and an open position, the sealing portion of the poppet positioned against the seat and inhibiting fluid flow past the seat while the poppet is in the closed position, the poppet spaced apart from the seat and permitting fluid flow past the seat while the poppet is in the open position; a guide portion coupled to the seat and including a first guide surface and a second guide surface; a first stem coupled to the poppet, the first stem including a first roller for engaging the first guide surface; a second stem coupled to the poppet, the second stem including a second roller for engaging the second guide surface; and a biasing member coupled between the first stem and the second stem, the biasing member exerting a biasing force to draw the first stem and the second stem toward one another, thereby biasing the sealing portion of the poppet against the sealing edge while the poppet is in the closed position, the first guide surface and the second guide surface having a shape that transfers at least a portion of the biasing force in a direction that is normal to the sealing edge while the poppet is in the closed position.
In some aspects, the first guide surface includes a first inclined portion and the second guide surface includes a second inclined portion, the first inclined portion and the second inclined portion extending away from the seat in diverging directions.
In some aspects, as the poppet moves from the closed position to the open position, a biasing force exerted by the biasing member on the first stem increases as the first roller moves along the first guide surface.
In some aspects, the poppet includes a first elongated slot and a second elongated slot, wherein the first stem extends through and is movable within the first elongated slot and the second stem extends through and is movable within the second elongated slot.
In some aspects, the poppet is configured to be supported for pivoting movement relative to the housing of the backflow preventer, wherein when the poppet is in a fully opened position, the poppet is out of a fluid flow path.
Other aspects of the disclosure will become apparent by consideration of the detailed description and accompanying drawings.
Before any embodiments are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of the configuration and arrangement of components set forth in the following description or illustrated in the accompanying drawings. The disclosure is capable of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof are meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings.
The seat 14 may include a seal groove 26, and a seal (e.g., O-ring) may be positioned in the seal groove 26 and seal between the seat 14 and a round pipe, valve body, housing, or the like. As shown in
As shown in
In some embodiments, biasing members 82 (e.g., extension springs) are coupled between the upper stem 58 and the lower stem 50. The force created by the one or more biasing members 82 may bias the upper stem 58 and lower stem 50 toward one another. The shape or profile of the upper guide tracks 46, the lower guide holders 34, and lower guide tracks 38 cause a portion of this spring force to bias the poppet 78 towards the seat 14. The number and strength of the biasing members 82 can be changed depending on the requirements of the system the guided check valve 10 is installed in.
When a force applied by fluid pressure on the inlet side 86 of the guided check valve 10 exceeds the combined force of the effective horizontal biasing force and the force applied by fluid pressure on the outlet side 90 of the guided check valve 10, the poppet 78 will begin to move from the closed position. As the poppet 78 moves, the upper guide rollers 62 slide or roll along the upper guide tracks 46 and the lower guide rollers 54 slide or roll out of the lower guide holders 34 and along the lower guide tracks 38 as illustrated in
In a first opening position (
In the first opening position, the upper stem 58 moves upward within the upper stem slot 98 and the upper guide rollers 62 move upward along the inclined surface of upper guide tracks 46. Similarly, the lower stem 50 moves downward within the lower stem slot 94 and the lower guide rollers 54 move downward along the inclined surface of the lower guide holders 34 (e.g., the surface of the lower guide holders 34 diverges from the surface of the upper guide rollers 62 as the surfaces extend away from the seat 14). As such, the distance between the upper stem 58 and lower stem 50 increases, and the springs or biasing members 82 coupled to the upper stem 58 and lower stem 50 resist or bias against this movement and increased distance, thereby creating an effective horizontal biasing force on the poppet 78. As shown in the illustrated embodiment, the surface of lower guide holders 34 may be curved such that the incline or angle of the surface is not constant. In some embodiments, the surface of the upper guide tracks 46 may be curved or otherwise have a non-constant surface angle or incline.
In a second opening position (
The surface or profile of the lower guide track 38 and upper guide track 46 may be configured such that the upper stem 58 and lower stem 50 continue moving further apart as the poppet 78 pivots open, increasing the magnitude of the biasing force of the one or more biasing members 82 that biases the upper stem 58 and lower stem 50 towards each other. The amount of effective closing force that biases the poppet 78 in the closed direction may be a function of (i) the magnitude of the biasing force that biases the upper stem 58 and lower stem 50 towards each other and (ii) the angle θ1 between the line of action 84 of the biasing force of the biasing members 82 (e.g., in the direction between the upper stem 58 and lower stem 50) and a line of tangency 36 of the surface of the lower guide track 38 or lower guide holder 34 where the lower guide roller 54 contacts the lower guide track 38 or lower guide holder 34 (e.g., a plane normal to the surface of the lower guide track 38 or lower guide holder 34 at the point of contact of the lower guide roller 54).
Specifically, the effective closing force that biases the poppet 78 closed may at least partially be a cosine function of θ1. As the line of action 84 approaches a normal or perpendicular orientation relative to the line of tangency 36 at the point of contact of lower guide roller 54 (i.e., θ1 approaches ninety degrees), little to none of the biasing force of the biasing member 82 is translated through the lower stem 50 into an effective closing force of the poppet 78 (i.e., the cosine function factor approaches zero). As the line of action 84 deviates from a normal or perpendicular orientation towards a parallel orientation relative to the line of tangency 36 (i.e., θ1 decreases towards zero degrees or increases towards one hundred eighty degrees), more of the biasing force of the biasing member 82 is translated through the lower stem 50 into an effective closing force of the poppet 78 (i.e., the cosine function factor increases). When the upper guide rollers 62 are in contact with the upper guide tracks 46 and the upper stem 58 has not bottomed out at a lowest position in the upper stem slot 98, the effective closing force may also be a function of the angle θ2 between the line of action 84 of the biasing force of the biasing members 82 and a line of tangency 48 of the surface of the upper guide tracks 46 where the upper guide roller 62 contacts the upper guide tracks 46.
In a third opening position (
At a fully open position (
If the force provided by fluid pressure to the inlet side 86 of the poppet 78 decreases below the force provided by fluid pressure to the outlet side 90 of the poppet 78 combined with the effective closing force provided by the one or more biasing members 82, the check valve 10 will close, moving back through the positions shown to the closed position (
As shown in
The configuration of the valve 10 and the closing mechanism for the poppet 78 also can provide a compact design with minimal moving components and especially minimal moving components in the normal flow area through the valve 10. The biasing members 82, stems 50, 58, and associated components may generally be provided on the downstream side of the poppet 78 such that they are not exposed to the primary flow. Similarly, the guides 30 may be positioned near a peripheral edge of the valve 10 such that the guides 30 also are not exposed to a central or main area of flow. Thus, the valve 10 can provide a compact and robust design that protects against backflow while reducing pressure loss during normal operating conditions.
In other embodiments, other configurations are possible. For example, those of skill in the art will recognize, according to the principles and concepts disclosed herein, that various combinations, sub-combinations, and substitutions of the components discussed above can provide a guided check valve.
The embodiment(s) described above and illustrated in the figures are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present disclosure. It will be understood that certain features and sub combinations are of utility and may be employed without reference to other features and sub combinations. Features described and illustrated with respect to certain embodiments may also be implemented in other embodiments. This is contemplated by and is within the scope of the claims. Since many possible embodiments of the disclosure may be made without departing from the scope thereof, it is also to be understood that all matters herein set forth or shown in the accompanying drawings are to be interpreted as illustrative and not limiting. As such, it will be appreciated that variations and modifications to the elements and their configuration and/or arrangement exist within the spirit and scope of one or more independent aspects as described.
This application claims the benefit of U.S. Provisional Patent Application No. 63/599,847 filed Nov. 16, 2023, the entire contents of which is incorporated by reference herein.
Number | Date | Country | |
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63599847 | Nov 2023 | US |