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.

