Backflow prevention assembly having a variable lay-length and orientation

A backflow prevention assembly is configurable with varying lay-lengths and orientations. The assembly includes coupling assemblies and valve bodies that adjust in length and/or rotation to allow for the varying lay-lengths and orientations of the backflow prevention valves and assemblies with and without certification. A coupling assembly is connected to a backflow prevention valve and includes an outer sleeve and an inner sleeve that is slidingly received within the outer sleeve. The lay-length is adjusted by slidably moving the inner and outer sleeves with respect to one another.

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 variable lay-length and orientation.

BACKGROUND

In many water systems, backflow prevention valves and assemblies allow fluid and even solids to flow in a desired direction (i.e., a forward direction). As backsiphonage or backflow may present contamination and health problems, the backflow prevention valves and assemblies prevent flow in an undesired direction (i.e., a backward or reverse direction). For example, backflow prevention valves and 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 backflow prevention assembly includes an inlet shutoff valve and an outlet shutoff valve with a backflow prevention valve extending between the inlet and outlet shutoff valves. Many different configurations of backflow prevention assemblies are commercially available, each being different in configuration and resulting lay-length. As used herein, “lay-length” is the distance between the ends of the backflow prevention valve or, if the valve is included in an assembly, the distance between the distal ends of the shutoff valves.

The backflow prevention valve and shutoff valves of the assemblies are normally threaded or bolted together with a fixed lay-length. As such, if a retrofit or replacement of an existing valve or assembly is desired, spools and spacing flanges are often required to be added to the replacement valve or assembly so that the lay-length of the replacement valve or assembly will match the lay-length of the existing valve or assembly in order to fit into the space left by the existing valve or assembly in the fluid system. Such spools require advance measurement, planning and ordering of parts that can create delay and expense in the retrofit process. To accommodate varying lay-lengths, the spools may be cut or manufactured to a custom length.

Additionally, backflow prevention assemblies require certification by various entities so that in-field reconfiguration is not possible while maintaining the certification. One exemplary certification organization that protects drinking water supplies is the Foundation for Cross-Connection Control and Hydraulic Research established by the University of Southern California. The approval process requires a laboratory evaluation in which the design is reviewed and then tested in a laboratory. For example, one of the important tests is the pressure loss across the backflow prevention assembly. The backflow prevention assembly must maintain pressure loss and other parameters within allowed limits. Life cycle and back pressure tests are also required. The approval process also requires an extensive one-year of field evaluation in which the subject assemblies are taken apart to insure no deformation, damage or problems occurred that could cause poor performance. Every three years, the certification for the backflow prevention assembly must be renewed. As such, one cannot simply disassemble and reconfigure a backflow prevention assembly in the field without voiding its certification.

SUMMARY

The present disclosure provides a new and improved backflow prevention valve and assembly having a variable lay-length that quickly and easily adjusts to the fluid system for easy retrofit and installation without need of a custom fit, fixed-length spool. The new and improved backflow prevention valve and assembly and associated variable-length coupling assemblies can be pre-certified by the manufacturer for adjustment of the lay-length during installations in the field in retrofit applications. Thus, in-field adjustments to lay-length may be made without additional parts while maintaining certification.

Among other aspects and advantages, the new and improved backflow prevention valve and assembly of the present disclosure can accommodate self-adjustment while in service. For example, thermal expansion, seismic activity, movement related to thermal cycles like freezing and the like may create expansion and contraction forces on the backflow prevention valve and assembly which the variable lay-length absorbs by the inherent ability to freely lengthen and shorten.

According to one aspect of the present disclosure, the variable lay-length is obtained using coupling assemblies that can vary in longitudinal length. According to another aspect, the variable lay-length is obtained using a valve housing that can vary in longitudinal length.

According to a further aspect of the present disclosure, the variable length coupling and the variable length valve housing are also rotatable about a longitudinal axis. The rotation allows for an orientation of the backflow prevention valve and assembly of the present disclosure to be varied, accommodates easier installation during retrofit applications, and permits more self-adjustment while in service.

According to a further aspect of the present disclosure, there is a backflow prevention assembly, comprising: a first shutoff valve; a second shutoff valve; an outer sleeve connected to one of the first and second shutoff valves; an inner sleeve connected to the other of the first and second shutoff valves and slidingly received within the outer sleeve such that a lay-length of the backflow prevention assembly can be varied; a fluid seal positioned between the inner sleeve and the outer sleeve; and a check valve, connected to the inner sleeve, configured to allow fluid flow through the backflow prevention assembly in a single direction.

According to a further aspect of the present disclosure, there is a backflow prevention assembly, comprising: a first shutoff valve; a second shutoff valve; a first backflow prevention valve connected between the first and second shutoff valves; and a coupling assembly connected to at least one of the first backflow prevention valve, the first shutoff valve and the second shutoff valve, wherein the coupling assembly, the first backflow prevention valve and the first and second shutoff valves define a lay-length of the backflow prevention assembly. The coupling assembly includes: a first end; a second end; an outer sleeve extending from the first end; an inner sleeve extending from the second end and slidingly received within the outer sleeve such that a distance between the first and second ends of the coupling assembly can be varied to adjust the lay-length of the backflow prevention assembly; and a fluid seal positioned between the inner sleeve and the outer sleeve.

According to a further aspect of the present disclosure, there is a backflow prevention assembly having a variable lay-length, comprising: a first shutoff valve; a second shutoff valve; a first backflow prevention valve connected between the first shutoff valve and the second shutoff valve; and a coupling assembly, connected to at least one of the first backflow prevention valve. The first shutoff valve or the second shutoff valve, includes: a first end; a second end; an outer sleeve extending from the first end; an inner sleeve extending from the second end and slidingly received within the outer sleeve; and a fluid seal positioned between the inner sleeve and the outer sleeve, wherein the lay-length is varied by sliding the inner and outer sleeves with respect to one another along a common axis.

DETAILED DESCRIPTION

This application is a non-provisional application claiming priority from U.S. provisional patent application, Ser. No. 62/691,037, filed Jun. 28, 2018 and entitled “Backflow Prevention Assembly Having A Variable Lay-Length And Orientation,” the entire contents of which is incorporated by reference herein for all purposes.

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.

In brief, the subject technology is directed to backflow prevention valves and assemblies that have varying lay-lengths and orientations and may include coupling assemblies and valve bodies that adjust in length and/or rotation to allow the varying lay-lengths and orientations of the backflow prevention valves and assemblies with and without certification.

Referring now toFIG. 1a, there is shown a backflow prevention assembly10in accordance with the subject technology. The backflow prevention assembly10is installed in a fluid system20(e.g., a water supply for a building mounted at a location in the ground23). The fluid system20includes fluid conduits that carry fluid in a forward direction (e.g., left to right inFIG. 1a) with the backflow prevention assembly10preventing flow in the backward direction (e.g., right to left inFIG. 1a). The fluid system20will include strainers, meters and other typical components that are not shown inFIG. 1a. The fluid system20has pipes22that terminate in opposing ends fitted with mounting flanges24a,24b. Typically, the distance between the mounting flanges24a,24bis fixed so that when installing the backflow prevention assembly10, a lay-length18of the backflow prevention assembly10should be matched to the distance between the mounting flanges24a,24b. The backflow prevention assembly10may be mounted horizontally or vertically as well as in parallel with another component such as even another backflow prevention assembly.

The backflow prevention assembly10can be modular and may include identical or functionally similar components so that some components may be interchanged. The backflow prevention assembly10includes an inlet shutoff valve12aand an outlet shutoff valve12b. Each shutoff valve12a,12bcouples to a respective flange24a,24bof the fluid system20. The shutoff valves12a,12bmay be interchangeable. The backflow prevention assembly10also includes two backflow prevention valves14a,14b, also referred to as “check valves,” connected to a respective shutoff valve12a,12b. The two backflow prevention valves14a,14bmay be interchangeable.

An exemplary embodiment of a backflow prevention valve14x, as known to one of ordinary skill in the art, is shown, in an exploded view, inFIG. 1e. Accordingly, a check valve assembly50includes a seat O-ring52, a seat54, a disk and spring assembly56, a cover O-ring58and a cover60. The seat O-ring52and the cover O-ring58provide a fluid seal.

Owing to the fact that a backflow prevention assembly is critical for water safety, it is tested, for example, annually, to assure that it is in proper operating condition. Specifically, as is known, fluid pressure measurements are taken at specified locations in the backflow prevention assembly10. To facilitate these pressure measurements, the backflow prevention assembly10includes a number of test cocks30, each of which includes a ball valve, and which is threadably connected to couple with a fluid path within the backflow prevention assembly10via a corresponding test cock port (not shown).

In a known implementation, four test cocks are located on the backflow prevention assembly10in order to allow for temporarily attaching measuring equipment to measure the flow to ensure that the backflow prevention assembly10is functioning correctly. Thus, for example, a test cock may be provided to measure the pressure coming into the backflow prevention assembly10; another test cock measures the pressure just before a first check valve; a third test cock measures the pressure right after the first check valve; and a fourth test cock measures the pressure right after a second check valve.

While not all test cocks30are shown in the Figures, a test cock30ais shown as provided on the backflow prevention valve14aand a test cock30bis provided on the backflow prevention valve14b. One of ordinary skill in the art will understand where other test cocks are placed in order to provide for a testable backflow prevention assembly10.

In the exemplary embodiment of the assembly10shown inFIG. 1a, a variable length coupling assembly100extends between the two check valves14a,14b. The variable length of the coupling assembly100allows the overall lay-length18of the backflow prevention assembly10to be adjusted to match the fixed distance between the mounting flanges24a,24bfor easy and quick installation. In the exemplary embodiment shown, the coupling assembly100also is rotatable about its length to allow for efficient alignment of the components.

The backflow prevention assembly10being modular allows for several varying configurations. InFIG. 1b, for example, the coupling assembly100extends between the inlet shutoff valve12aand the check valve14a. Similarly, the coupling assembly100could be located between the check valve14band the outlet shutoff valve12b. For another example shown inFIG. 1c, the coupling assembly100extends from the outlet shutoff valve12bfor connection to the mounting flange24bto act as an adjustable coupling. Alternatively, the coupling assembly100could extend from the inlet shutoff valve12afor connection to the mounting flange24a.

For another example, as shown inFIG. 1d, the coupling assembly100can be provided to extend vertically, with respect to the ground23, between the input and its respective shutoff valve12aand the output and its respective shutoff valve12b. In addition, the coupling assembly100can be vertically placed between the shutoff valve12aand the check valve14aand between the shutoff valve12band the check valve14b. Further, and similar to the configuration inFIG. 1a, the coupling assembly100can be placed horizontally between the check valve14aand the check valve14b. It should be noted that while two vertically-oriented sections are shown inFIG. 1dwith the coupling assemblies100, one of ordinary skill in the art will understand that it is not necessary that both be constructed as such and the claims are not intended to be limited to the embodiment shown inFIG. 1d

An exemplary embodiment of the coupling assembly100is shown inFIGS. 2 and 3a. The coupling includes first and second ends102,104, an outer sleeve110extending from the first end102, and an inner sleeve120extending from the second end and slidingly received within the outer sleeve such that a length140between the first and the second ends102,104of the coupling assembly100can be varied to vary the lay-length18of the backflow prevention assembly10ofFIGS. 1athrough1d. The outer sleeve110has an open distal end112receiving an open distal end122of the inner sleeve. A fluid seal130is positioned between the inner sleeve120and the outer sleeve110to provide a fluid-tight seal between the sleeves, yet allow sliding movement between sleeves. The fluid seal may comprise, for example, an O-ring130. As discussed below, the present disclosure also includes the addition of one or more springs, or another type of biasing feature, in the coupling assembly100to cause the sleeves to be biased, or urged, away from one another along their common axis.

As shown inFIG. 3a, the sleeves110,120have circular cross-sections so that the sleeves can rotate with respect to each other about a longitudinal axis150of the coupling assembly100. In alternative embodiments, the sleeves may have non-circular cross-sections to prevent rotation with respect to one another. For example, inFIG. 3bthe coupling assembly100is shown with an outer sleeve110aand an inner sleeve120aeach having an oval-shaped cross-section that prevent rotation with respect to each other.

In the exemplary embodiment ofFIGS. 2 through 3b, the ends102,104of the coupling assembly100comprise flanges for connection to the other components of the backflow prevention assembly10and/or the mounting flanges24a,24bof the fluid system20. It should be noted, however, that the ends could take other forms to facilitate connection of the coupling assembly100to the backflow prevention assembly10and/or the fluid system20. In addition, it should be understood that one or both of the ends102,104of the coupling assembly100could be unitarily formed with the check valves14a,14band/or the shutoff valves12a,12b. For example, the first end102and the outer sleeve110could be unitarily formed with the check valve14a, and the second end104and the inner sleeve120could be unitarily formed with the check valve14b.

Referring now toFIG. 4, a partial cross-sectional view of an exemplary embodiment of a coupling assembly100ain accordance with the subject technology is shown. The coupling assembly100ais similar to the coupling assembly100ofFIGS. 2 and 3a, but includes a snap ring160received in a radially inwardly facing groove114of the outer sleeve110. The inner sleeve120includes a flange124at its distal end122that, in combination with the snap ring160, holds the inner sleeve120within the outer sleeve110. As discussed below, the present disclosure also includes the addition of one or more springs, or another type of biasing feature, in the coupling assembly100ato cause the sleeves to be, or urged, away from one another along their common axis.

Referring now toFIG. 5, a partial cross-sectional view of another coupling assembly100bin accordance with the subject technology is shown. The coupling assembly100bis similar to the coupling assembly100ofFIGS. 2 and 3a, but includes a groove211in the flange of the first end102for receiving an O-ring213to provide a fluid tight seal to the flange of the first end102. The coupling flange of the first end102and the fluid system flange24amay be tightly held together by one or more retaining clips215that snap onto the flange24aand the flange of the first end102. The inner sleeve120includes two radially outwardly facing annular channels217for retaining respective O-rings219to insure fluid tight sealing between the sleeves120,110. In this embodiment of the coupling assembly100b, the sleeves120,110are rotatable and slidable but a retention feature is not needed because the backflow prevention assembly100maximum installed length will not allow for the sleeves120,110to be disengaged from one another. In an alternate approach, as would be understood by one of ordinary skill in the art, a clamp ring can be used in place of the retaining clip215.

Referring now toFIG. 6, a partial cross-sectional view of another coupling assembly100cin accordance with the subject technology is shown. The coupling assembly100cis similar to the coupling assembly100ofFIGS. 2 and 3a, but the outer sleeve110includes a narrowed inner diameter that forms a minimum lay-length travel stop321for the inner sleeve120. The flange of the first end102of the coupling assembly100cis secured to the flange24busing a threaded union nut323.

Referring now toFIGS. 7 and 8, additional embodiments of certified backflow prevention assemblies40a,40b, are shown, each having one or more variable length and/or rotatable coupling assembly500in accordance with the subject disclosure. Each coupling assembly500ofFIGS. 7 and 8is generally similar to the coupling assembly100ofFIGS. 1athrough 1d. Each of the backflow assemblies40a,40bincludes a backflow prevention valve44, a first shut-off valve42a, and a second shut-off valve42b. As can be seen fromFIG. 8, an overall height49of the backflow prevention assembly40bcan be changed by adjusting the length of the coupling assemblies500a,500d. A lay-length48of the assembly can be changed by adjusting the length of one or both of the coupling assemblies500b,500c. In addition, the orientation of the assembly40bcan be varied such that the shut-off valves42a,44bpoint in different directions by rotating one or both of the coupling assemblies500b,500c. For example, as shown inFIG. 8both shut-off valves42a,44bpoint downward. However, the coupling assembly500ccould be rotated so that the second shut-off valve44bpoints upward.

In addition, similar to the backflow prevention assembly10ofFIGS. 1a-1d, a number of test cocks30-1-30-4are provided in order to measure the operating condition of the backflow prevention assemblies40a,40b.

Referring now toFIG. 9, a partial cross-sectional view of an exemplary embodiment of a coupling assembly500in accordance with the subject technology is shown. The coupling assembly500is similar to the coupling assembly100ofFIGS. 2 and 3a, and similar elements are indicated with like reference numbers in the “500” series instead of the “100” series. The coupling assembly500incorporates a press fitting seal ring511in an outer sleeve510that retains an O-ring530. In one approach, the coupling assembly500is installed without crimping the seal ring511. The O-ring530still will provide a fluid tight seal, but the sleeves510,520will be allowed to slide and rotate and a length540will remain variable so that subsequent expansion and contraction is possible post-installation.

Alternatively, the press fitting seal ring511can be crimped to fix the length540(and rotation) of the coupling assembly500. In the exemplary embodiment shown, a second end504of the coupling assembly500is secured to the shut-off valve42awith solder560, and the first end502of the coupling assembly500includes a threaded union nut562for connecting the coupling assembly500to the backflow prevention valve44.

Referring now toFIG. 10, a cross-sectional view of another exemplary embodiment of a coupling assembly600in accordance with the subject technology is shown. The coupling assembly600is similar to the coupling assembly100ofFIGS. 2and3a, and similar elements are indicated with like reference numbers in the “600” series instead of the “100” series. The coupling assembly600incorporates a quick connect fitting for coupling sleeves610,620together.

In one approach, the quick connect fitting is a push-to-connect fitting670so that soldering, crimping or joining materials are not required. The push-to-connect fitting670includes a collet672, a cap674, an O-ring guide676, and a clip678for locking the fitting. For assembly, it is only required to push the inner sleeve620into the outer sleeve610. Removing the clip678and pushing in the collet672allows the sleeve620to be removed. Examples of push-to-connect fittings and press fittings that can be incorporated into the subject technology can be found at www.watts.com.

Referring now toFIG. 11, another exemplary embodiment of a backflow prevention assembly1010is shown. The assembly1010includes a backflow prevention valve1100having an inner sleeve1120containing a first check valve1500and a second check valve1600. The inner sleeve1120is slidingly received within an outer sleeve1110such that a lay-length1140of the assembly1010can be varied. O-rings1130provide a seal between the sleeves1110,1120yet allow the inner sleeve1120to slide within the outer sleeve1110. The sleeves1110,1120may be provided with circular cross-sections so that the sleeves1110,1120can rotate with respect to each other about a longitudinal axis1150of the assembly1010. In alternative embodiments, the sleeves may have non-circular cross-sections to prevent such relative rotation.

The valve1100can include a feature for biasing the sleeves1110,1120away from one another along the longitudinal axis1150. In the exemplary embodiment, the biasing feature includes compression springs1108(shown schematically) positioned between the sleeves1110,1120. This springs1108may be separate from both of the sleeves1110,1120or one end of a spring may be attached to one or the other of the sleeves1110,1120.

While a coil, or helical, spring1108is shown, other components or structures that store mechanical energy can be used, for example, but not limited to, a leaf spring or a cantilever spring. Further, the biasing feature may have a constant force, i.e., a forceful resistance that remains the same during a deflection cycle or a variable force, i.e., a force or resistance that varies as it is compressed.

In the exemplary embodiment shown inFIG. 11, the backflow prevention assembly1010includes a first coupling sleeve1200slidingly receiving a first end1102of the valve1100and a second coupling sleeve1300slidingly receiving a second end1104of the valve1100. The coupling sleeves1200,1300allow the lay-length1140the backflow prevention assembly1010to be further expanded. The sleeves1110,1120,1200,1300may be provided with circular cross-sections so that the sleeves can rotate with respect to each other about the longitudinal axis1150of the backflow prevention assembly1010. In alternative embodiments, one or more of the sleeves1110,1120,1200,1300may have non-circular cross-sections to prevent such relative rotation.

Although not shown, the backflow prevention assembly1010may further include a feature for fixing, or locking, one or more of the sleeves1110,1120,1200,1300in position after installation of the backflow prevention assembly1010in a fluid system. For example, the backflow prevention assembly1010could include bolts for securing the first coupling sleeve1200to the outer sleeve1110to prevent sliding or rotation between the sleeves1200,1110after installation of the backflow prevention assembly1010.

In the exemplary embodiment shown inFIG. 11, the backflow prevention assembly1010includes test cock valves1400(shown schematically). The test cock valves1400are for use to facilitate testing of the backflow prevention assembly1010. During testing procedures, pressure gauges (not shown) are connected to the test cock valves1400and the test cock valves are opened. Backflow assemblies with test cock valves are currently designated as “testable.”

Another exemplary embodiment of a backflow prevention assembly is shown inFIG. 12. The backflow prevention assembly2000is a variation of the assembly1010and has the same arrangements of components as the assembly1010except for the feature for biasing the sleeves1110,1120away from one another along the longitudinal axis1150. Instead of two springs1108, the assembly2000includes a single spring2108that is sized to slidably fit within the outer sleeve1110to exert a force against the inner sleeve1120such that a lay-length1140of the assembly2000can be varied. Alternatively, the single spring2108can be replaced by two or more springs as would be understood by one of ordinary skill in the art. The assembly2000otherwise operates in the same manner as the assembly1010.

The variable lay-length1140of the backflow prevention assembly1010expedites service (especially for those backflow assemblies currently designated as “testable”) or replacement operations (especially for those backflow assemblies currently designated as “untestable”). By locking the backflow prevention assembly1010in an expanded position after installation (larger than that of the open pipe section, but less than that which would restrict movement at one or both ends of the assembly1010) the backflow prevention assembly1010is allowed to float, or vary by length, along the longitudinal axis1150and between the fixed ends of a fluid system. If the sleeves1110,1120,1200,1300include circular cross-sections, the backflow prevention assembly1010or parts thereof may be allowed to be rotated about the longitudinal axis1150between the fixed ends of a fluid system.

To perform service or replacement, one need only to push the two central sleeves1110,1120together against the force of the springs1108, allowing the valve1100to be removed from the coupling sleeves1200,1300. Once removed, the sleeves1110,1120can be disassembled and the check valves1500,1600removed for inspection, repair or replacement as desired. Reversing the removal steps returns the backflow prevention assembly1010to normal operating conditions.

In another aspect of the present disclosure, any of the foregoing assemblies can include a reduced pressure zone assembly, for example, the Series 880V MasterSeries Configurable Design Reduced Pressure Zone Assembly from Watts, provided between the check valves.

Backflow prevention valves and assemblies need to be certified by a qualified certifying agency in order to comply with various regulations. Such certifying agencies can include the Foundation for Cross-Connection Control and Hydraulic Research (FCCCHR), American Society of Sanitary Engineers (ASSE), The American Water Works Association (AWWA), The International Association of Plumbing and Mechanical Officials (IAPMO), Underwriters Laboratories (UL), and Canadian Standards Association (CSA) International, for example. The backflow prevention assemblies disclosed herein can be certified from shut-off valve to shut-off valve from the place of manufacture before they are installed in replacement sites. The certifications allow the lay-length and orientation of the assemblies to be varied by installers in the field such that the assemblies can be installed in replacement of existing assemblies that may have had a different lay-length.

The subject components may be fabricated from any suitable material or combination of materials such as lightweight stainless steel, epoxy coated carbon steel, zinc plated carbon steel, copper, copper alloys, suitable plastics and composites, and the like.

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