Backflow prevention assembly with telescoping bias assembly and reversible valve member

A valve assembly with a spring retention assembly including an elongated cylinder portion having an open threaded end and a closed end and an elongated piston portion having a free end and a threaded tab end configured to thread through the open threaded end and, thereby, be slideably captured in the cylinder portion. A spring couples to the body portion and the piston portion to provide a force to urge the body portion and the piston away from one another, wherein the closed end and the free end are similarly shaped so that the spring retention assembly can be reversibly mounted to a valve member that can also be reversibly mounted.

FIELD OF THE DISCLOSURE

The subject disclosure relates to backflow prevention valves and assemblies, and more particularly to backflow prevention valves and assemblies having a reversible telescoping bias spring retention assembly coupled to a reversible valve member.

BACKGROUND

In many water systems, backflow prevention (BFP) assemblies allow fluid and even solids to flow only in a desired, i.e., a forward, direction. As backsiphonage or backflow can present contamination and health problems, the backflow prevention valves and assemblies prevent flow in an undesired direction, i.e., a backward or reverse direction. BFP assemblies are installed in buildings, such as residential homes, and commercial buildings and factories, to protect public water supplies by preventing the reverse flow of water from the buildings back into the public water supply.

A typical BFP assembly includes an inlet shutoff valve and an outlet shutoff valve with a backflow prevention valve assembly extending between the inlet and outlet shutoff valves. Many different configurations of BFP assemblies are commercially available, each being differently configured.

Owing to the fact that BFP assemblies are important for water safety, BFP units are tested annually, often per government regulations, to assure proper operating condition. Specifically, fluid pressure measurements are taken at specified locations in the BFP unit. If it is determined that a check valve needs to be repaired or replaced, the inlet and outlet shutoff valves have to be closed, the check valve fixed and tested, the shutoff valves opened and the apparatus confirmed to be operating per any required ordinances and/or standards. The process is time-consuming and the steps have to be performed in the correct sequence and manner in order to not contaminate the public water supply, inadvertently flood an area, and return the BFP assembly to working order.

SUMMARY

From time to time, various components of a BFP assembly may need replacement, which is not only difficult and time consuming but results in downtime for the fluid network. Components for the BFP assembly that are easier to manufacture, assemble and install as well as more robust would reduce: the difficulty of fabrication and repair; repair time; assembly error from improper fabrication or otherwise; and the difficulty of installation. Preferably, a telescoping spring retainer assembly provides some or all of these benefits along with reducing the required components. When the telescoping spring retainer assembly is coupled to a reversible valve member, these benefits are further enhanced.

The subject technology is directed to a valve assembly including a spring retention assembly coupled to a valve member. The spring retention assembly has an elongated cylinder portion having an open threaded end and a closed end. An elongated piston portion has a free end and a threaded tab end configured to thread through the open threaded end and, thereby, be slideably captured in the cylinder portion. A spring couples to the body portion and the piston portion to provide a force to urge the body portion and the piston away from one another, wherein the closed end and the free end are similarly shaped so that the spring retention assembly can be reversibly mounted. A valve member includes a central disc having a first side and a second side, each side forming a sealing region and having a retention cup, wherein both retention cups can capture the closed end or the free end so that the valve member is reversible. A hinge portion extends radially from the central disc.

In one embodiment, the subject disclosure is directed to a spring retention assembly for a valve assembly, comprising an elongated cylinder portion having an open threaded end and a closed end. An elongated piston portion has a free end and a threaded tab end configured to thread through the open threaded end and, thereby, be slideably captured in the cylinder portion. A helical spring couples to the body portion and the piston portion to provide a force to urge the body portion and the piston away from one another, wherein the closed end and the free end are similarly shaped so that the spring retention assembly can be reversibly mounted.

In another embodiment, the subject disclosure is directed to a spring retention assembly for a valve assembly having a cylinder portion with an open threaded end. A piston portion has a threaded tab end configured to thread through the open threaded end and, thereby, be captured in the cylinder portion for sliding motion. A spring couples to the body portion and the piston portion to provide a force to urge the body portion and the piston away from one another. Preferably, the cylinder portion has a closed end with a retention collar, the piston portion has a retention collar, and the spring extends between the retention collars. The spring may be under a predetermined amount of compression less than an amount of force of a normal forward flow of fluid in the backflow prevention system. The inner diameter of the cylinder portion and an outer diameter of the threaded tab end can be approximately equal so that lateral movement of the piston portion is reduced.

In still another embodiment, the subject disclosure is directed to a spring retention assembly for a valve assembly that includes a telescoping central portion with a first free end and a second free end, wherein the ends are similarly shaped so that the spring retention assembly can be reversibly mounted. Preferably, the ends are bulbous to fit in a hollow formed in the housing of the valve assembly or a retention cup of the valve element. Another embodiment includes a first retention collar on the first free end, a second retention collar on the second free end, and a spring extending between the retention collars so that the ends are configured to mount to either retention collar for simplification of the parts required.

The subject technology is also directed to a valve member for a valve assembly including a central disc having a first side and a second side, each side forming a sealing region and having a retention cup, wherein the sealing regions and the retention cups are similarly shaped so that the valve member is reversible. A hinge portion extends radially from the central disc. The sealing regions may be ring-shaped elastomeric inserts. Preferably, the retention cups are centrally located on the respective side with a plurality of deflectable fingers for receiving a spherical end of a spring retention assembly. By being the same shape and size, the deflectable fingers facilitate either side interacting with the spring retention assembly. By the first and second sides being symmetrical about an axis, reversibility of the valve member is also facilitated. In one embodiment, the hinge portion includes a pair of opposing arms extending radially from the central disc and having distal protruding tabs.

DETAILED DESCRIPTION

The subject technology overcomes many of the prior art problems associated with backflow prevention assemblies. The advantages, and other features of the technology disclosed herein, will become more readily apparent to those having ordinary skill in the art from the following detailed description of certain exemplary embodiments taken in combination with the drawings and wherein like reference numerals identify similar structural elements. It should be noted that directional indications such as vertical, horizontal, upward, downward, right, left and the like, are used with respect to the figures and not meant in a limiting manner.

Referring now toFIGS.1and2, there is shown a backflow prevention (BFP) assembly100in accordance with an aspect of the present disclosure. The BFP assembly100may be installed in a fluid system, e.g., a water supply for a building. In normal operation, the backflow prevention assembly100operates to carry fluid in only a forward direction, e.g., left to right inFIGS.1and2, from an inlet116to an outlet120. The BFP assembly100operates to prevent flow in a backward direction, i.e., a direction from right to left inFIGS.1and2.

The BFP assembly100includes a body104forming an upstream bucket108and a downstream bucket112. Each bucket108,112is enclosed by a test cover118,122. The test covers118,122may include one or more test cocks140for sensing pressure at various locations within the BFP assembly100. The downstream test cover118includes two test cocks140and the upstream test cover122includes a single test cock140but the test covers118,122are otherwise very similar.

Each bucket108,112includes a check valve assembly150for selectively opening and closing flow through the respective bucket108,112. Preferably, the check valve assemblies150are interchangeable although as shown, the check valve assemblies150are different. Each check valve assembly150has frame170fit into the respective bucket108,112. The frame170retains a valve member200, which selectively closes against a circular valve seat172of the frame170. The valve members200are generally disc-shaped with an annular sealing region204that seals against the valve seat170. The valve member200is connected to the frame170by a hinge portion206that allows rotation of the valve member200away from the valve seat172to open flow.

In each check valve assembly150, a spring retainer assembly300provides a biasing force to urge the valve member200against the valve seat172. If the pressure downstream of the valve member200exceeds the force of the spring retainer assembly300, the check valve assembly150will open to allow forward flow. If not, the spring retainer assembly300will keep the check valve assembly150closed. The spring retainer assembly300extends between the respective test cover118,122and the valve member200. The test covers118,122form hollows124for coupling to the spring retainer assembly300whereas the valve member200has a retention cup210for coupling to the spring retainer assembly300.

Referring now toFIGS.3-10, various views of the spring retainer assembly300are shown. The spring retainer assembly300includes a telescoping central portion302. The telescoping central portion302includes a somewhat tubular cylinder portion310with an open lip end312. The open lip end312has internal threads314best seen inFIGS.6and10. A closed free end316opposes the open lip end312and has a spherical or bulbous shape for coupling to the retention cup210of the valve member200or in the hollow124of the test cover118,122, as the case may be. Adjacent the bulbous closed free end316, a retention collar318is formed.

The spring retainer assembly300also includes a piston portion330that partially slides within the cylinder portion310. The piston portion330has a tab end332that is captured within the cylinder portion310. The tab end332has outer threads334. To couple the cylinder portion310and the piston portion330together, the tab end332is threaded through the open lip end312of the cylinder portion310. Once coupled, the tab end332can slide within the cylinder portion310but is retained by the lip end312until unscrewed.

The piston portion330has a free end336with a retention collar338. A spring350is captured and compressed between the retention collars318,338to urge the cylinder portion310and piston portion330apart as best seen inFIGS.3-5. Thus, when in the spring retainer assembly300is in place between the fixed rigid hollow124of a test cover118,122and retention cup210of the valve element200, the spring350provides the biasing force to urge the valve element200closed (seeFIGS.1and2).

As illustrated inFIGS.7-10and shown in the downstream check valve assembly150ofFIG.2, the spring retainer assembly300is compressed by opening of the check valve assembly150when the upstream pressure on the valve member200exceeds the force provided by the spring350. In other words, the force of the spring350is predetermined to allow the valve element200to permit the normal flow of fluid in the forward direction.

In order to minimize wobbling or lateral motion of the piston portion330during sliding, an inner diameter D1of the cylinder portion310is approximately the same as the outer diameter D2of the threaded tab end332(seeFIG.6). The threaded tab end332also has sufficient length along the axis of movement to be stable inside the cylinder portion310. In this way, the piston portion330moves linearly and is prevented from wobbling. The length of the threaded tab end332and cylinder portion310are selected to minimize wobbling while still allowing sufficient travel for a fully open and closed check valve150.

In normal operation, the force exerted by the respective spring retainer assembly300on the valve elements200is overcome by the pressure exerted by the fluid normally flowing from the inlet116to the outlet120so that both check valves150are open. If, for example, there is a drop in pressure from the supply source, the upstream valve element200and the downstream valve200will close to prevent backflow as shown inFIG.2. Similarly, if the normal forward flow is interrupted, one or both of the valve elements200is urged in position to cover the valve seat172(e.g.,FIGS.1and2, respectively) to close the check valve150and prevent backflow.

To assemble a check valve150, the threaded tab end332of the piston portion330is screwed through the threaded lip end312of the cylinder portion310to couple the piston portion330to the cylinder portion310. Either end316,336may be coupled to the retention cup210of the valve element200because each end316,336is similarly shaped. Preferably, the retention cup210is flexible and deforms slightly to receive the spherical end316,336without requiring any tools. Once popped in, the bulbous end316,336easily rotates within the retention cup210. As the test cover118is mounted is mounted on the check valve150, the other end316,336of the spring retention assembly300is aligned to the hollow124, which captures the end316,336while also allowing for easy rotation of the end316,336therein. Thus, the spring retention assembly300can be arranged in a reverse arrangement to that which is shown and assembly is simplified.

Repair of the spring retention assembly300is also simplified. For example, if the piston portion330is broken, the threaded tab end332is unthreaded from the cylinder portion310. To replace the broken piston portion330, a new piston portion330can be threaded into the previously used cylinder portion310. Similarly, without tools, the portions310,330can be separated to replace the helical spring350.

In one embodiment, the ends316,318include a spherical portion319having a threaded post321that screws into or otherwise mounts to the retention collar318,338. Hence, the threaded posts312are the same so that fewer parts are required and manufacturing and repair is simplified. Further, as tools are not required, assembly is simplified. In another embodiment, the ends316,318are different sizes to preclude reversibility. For example, only one end316,318may be small enough to fit into the retention cup210so that there is only one orientation that couples the spring retention assembly300to the valve element200.

In another embodiment, the spring retention assembly does not include a helical spring around the outside. Instead, the helical spring or even a compressible insert is provided with the cylinder portion to generate the proper bias.

Referring now toFIGS.11A and11B, isolated side and perspective views of a frame170for use in a check valve assembly in accordance with the subject disclosure are shown. The frame170snugly fits into the respective bucket. A top portion174seals against the BFP assembly body and a lower portion177narrows the fluid path through the BFP assembly to an opening175of the valve seat172. The top portion174includes a circular ledge182that acts as an insertion hardstop. A retaining nut126(seeFIG.1) threads onto the body104to secure the frame170thereto. The valve seat172also includes an annular raised rim176as a sealing surface with a recess178surrounding the rim176.

The frame170includes standoffs179adjacent the opening175and forming a pair of opposing notches180. The notches180may be U-shaped to receive a valve member such that the valve member is hinged to the frame170for selective opening and closing of the opening175. The notches180may also simply be holes or similar shape to receive a protruding tab to create a hinge arrangement.

Referring now toFIG.12, a partial cross-sectional view of a reversible valve member400coupled to a frame450in a check valve assembly of a BFP assembly in accordance with the subject disclosure is shown. Like reference numerals in the “400” series are used to refer to similar elements between the frame170and the frame470. Similarly “400” series numbers are also used to describe like elements between the valve members200,400so that the following description can be directed to the differences.

The valve member400is reversible by being symmetrical. The valve member400has a central disc402. Each side of the central disc402has a central retention cup410. The cups410have a plurality of fingers412that deflect to allow manual insertion of the end316of the spring retention assembly300to capture the end316therein. Once captured, the end316can smoothly rotate within the cup410like a ball-and-socket joint. Similar connections like a condyloid joint, saddle joint, hinge joint, pivot joint and the like may be used. The valve member400also has a radially outward ring-shaped sealing region404on each side408. An outer edge414of the central disc402may be relatively thicker than the sealing region404. The hinge portion406extends from the outer edge414of the central disc402. In one embodiment, the sealing surface476is a ring-shaped elastomeric insert on each side408.

Once assembled, as shown in the closed position inFIG.12, the spring retention assembly300urges the valve member400against the valve seat472. The sealing region404of the valve member400and the sealing surface476of the frame seat172are sealingly engaged to close the opening475. When the upstream fluid pressure exceeds the urging force of the spring retention assembly300, the valve member400rotates to open the opening475and, in turn, the end316rotates within the deflectable fingers412of the retention cup410.

By being symmetrical, the valve member400can be arranged in a reverse arrangement and work in the same manner. Thus, assembly is simplified. Further, repair of the valve member400is also simplified. For example, if the valve member400is broken on one side in the field, rather than locate a replacement part, the valve member400can be unhinged, flipped and rehinged. As a result, the required number of parts is reduced with assembly and repair simplified. Preferably, tools are also not required.

Referring now toFIGS.13A and13B, isolated views of another reversible valve member500for use in a check valve assembly in accordance with the subject disclosure are shown. As will be appreciated by those of ordinary skill in the pertinent art, the valve member500utilizes similar principles to the valve members200,400described above. Accordingly, like reference numerals in the “500” series are used to indicate like elements.

The primary difference of the valve member500is the sloped sealing region504as best seen inFIG.13B. The sloped sealing region504may be formed by partially fully coating the central disc502. Alternatively, the entire central disc502may be formed from an elastomeric or other material with the desired sealing properties. The valve member500is still symmetrical about an axis of symmetry “a” for reversibility.

The hinge portion506includes a pair of opposing radially extending flexible arms507. The arms507have distal tabs509protruding outward to engage the frame. By manually deflecting the arms507inward (e.g, closer together), the tabs509can be snap-fit into the notches of the frame. In another embodiment, the hinge portion and the standoff of the frame have transverse passages for receiving a hinge pin to create the hinge. It is envisioned that the tabs509may simply rest in the notches with the force of the spring assembly being sufficient so that the tabs509float in place to allow easy freedom of movement.

Referring now toFIG.14, an isolated perspective view of the telescoping spring retention assembly300coupled to the reversible valve member500in accordance with the subject disclosure is shown. Again, if the valve member500becomes damaged in the field (e.g., one of the cups512become broken), the valve member500can simply be flipped and reinstalled without tools in the check valve assembly. Similarly, the orientation of the valve member500and spring retention assembly during initial assembly is not important, which makes assembly easier.

Referring now toFIGS.15-18, various views of another spring retainer assembly600are shown. Similar elements to those described in connection with above-described embodiments are indicated with the like reference numbers in the “600” series. Many elements are essentially the same as those of the foregoing embodiments and, thus, are not further described herein. Thus, the following description relates to the differences of the spring retainer assembly600.

The spring retainer assembly600has a piston portion630with opposing buttons611near the end632for coupling to the cylinder portion610. The cylinder portion610forms opposing two-part slots613that capture the buttons611to guide the telescoping motion. Each two-part slot613has a cross-wise portion615and an axial portion617. During normal operation, the buttons611are captured in the axial portion617of the two-part slots613to guide linear motion and prevent the spring retainer assembly600from coming apart if the test cover is opened or removed. As shown inFIG.17, the spring retainer assembly600is fully extended.

To assembly the spring retainer assembly600, the piston portion630is pressed into the cylinder portion610. The cylinder portion610has angled internal ramps623that guide the buttons611into axial grooves625. The axial grooves625guide the buttons611in the cross-wise portion615of the two-part slot613(FIG.16). Once the buttons611are in the slot613, the piston portion630can be rotated along arrow627as shown inFIG.18to be in the operational position within the axial portion617of the slot613. In another embodiment, the buttons611are push-buttons that retract during insertion into the slot613. In still another embodiment, the slot613extends toward the open end (e.g., along the line of the groove625). The cylinder portion610may also be somewhat deformable so that the cylinder portion610can be flexed to insert the buttons611in the slots.

As can be seen, the subject disclosure provides many improvements to BFP assemblies100. For example, without limitation, the BFP assemblies100are more easily manufactured by simplification and/or reversibility of components. The assembly is not only easier but more error proof due to improved design of components. Similarly, repair is also faster, easier and less complex. Further, the subject technology can be adapted to any kind of valve.

It will be appreciated by those of ordinary skill in the pertinent art that the functions of several elements can, in alternative embodiments, be carried out by fewer elements, or a single element. Similarly, in some embodiments, any functional element can perform fewer, or different, operations than those described with respect to the illustrated embodiment. Also, functional elements (e.g., check valves, valve elements, spring retention assemblies, and the like) shown as distinct for purposes of illustration can be incorporated within other functional elements in a particular implementation.

While the subject technology has been described with respect to various embodiments, those skilled in the art will readily appreciate that various changes and/or modifications can be made to the subject technology without departing from the scope of the present disclosure.