A backflow prevention assembly includes a body forming two buckets, wherein flow passes through the body from an inlet to an outlet along an axis and consecutively through each of the buckets. A single zone test cover encloses a first of the buckets to form a single zone chamber. A dual zone test cover encloses a second of the buckets with a dual zone cartridge assembly therein. The dual zone test cover has two test cocks. The dual zone cartridge assembly includes a frame having a valve seat, wherein the frame includes a lumen providing fluid communication from a dual zone chamber upstream of the valve seat to a first of the two test cocks of the dual zone test cover, and wherein the second of the two test cocks of the dual zone test cover is in fluid communication with the dual zone chamber downstream of the valve seat.

A check valve for a backflow prevention assembly includes a linkage with a platform having a proximal end and a distal end and a first coupling member supported by the platform for engaging a bias assembly. A stop protrudes from the proximal end of the platform to engage a frame of the check valve for limiting travel of the platform. A branch depends from the proximal end of the platform, the branch having a hinge pin configured to nest in a slot defined by check valve. A second coupling member depends from the distal end of the platform for engaging a valve member.

A double check valve is provided that includes an in-line inlet check valve and an outlet check valve that cooperate to prevent back flow of fluid through the valve. The check valve also includes at least one vent that allows for fluid trapped within the check valve to drain, thereby preventing freezing of the check valve and hydrant to which it is interconnected. The check valve provided omits many superfluous components and thus is smaller and easier to install than check valves of the prior art.

A backflow prevention device includes a piston received in a device passage between an inlet port and outlet port. A relief port can fluidly communicate with a middle segment of the device passage. The piston is movable between a normal flow position in which the piston blocks fluid communication between the relief port and the middle segment of the device passage and a backflow position in which the piston allows fluid communication between the relief port and the middle segment of the device passage. The piston can move to the normal position in response to normal flow through the device passage from the inlet port toward the outlet port and configured to move to the backflow position in response to greater pressure in the middle segment than in the inlet port.

A double check valve is provided that includes an in-line inlet check valve and an outlet check valve that cooperate to prevent back flow of fluid through the valve. The check valve also includes at least one vent that allows for fluid trapped within the check valve to drain, thereby preventing freezing of the check valve and hydrant to which it is interconnected. The check valve provided omits many superfluous components and thus is smaller and easier to install than check valves of the prior art.

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.

An arrangement for managing a liquid medium, such as water, combines a pressure-reducing valve with two backflow prevention valves. Both the pressure-reducing valve and the two backflow prevention valves may be integrated into a common housing, specifically with both backflow prevention valves in an inlet chamber of the housing, wherein the inlet chamber and an outlet chamber of the housing are either fluidly coupled or isolated from one another by the pressure-reducing valve depending on the outlet chamber pressure prevailing in the outlet chamber. In some instances, a manually actuatable shut-off valve may be integrated into the housing. The manually actuatable shut-off valve may selectively keep the pressure-reducing valve in a closed position or allow the automatic opening and closing of the pressure-reducing valve depending on the outlet chamber pressure prevailing in the outlet chamber.

A check cover assembly for a backflow prevention (BFP) assembly including a dome-shaped base with an upstanding shroud, wherein the shroud forms an inner area configured to receive a test cock to support and protect the test cock. The shroud forms a gap for accessing the test cock to selectively open and close the test cock while installed in the inner area. The base forms a passageway from the inner area into the BFP assembly configured so that when the test cock is open, a pressure reading of a pressure zone in the BFP assembly can be taken via the test cock. A retention fork is in a slit formed in the shroud so that the test cock is captured in the inner area but the test cock can be removed from and inserted into the inner area without rotation when the retention fork is removed from the slit.

A backflow preventer including a body having an inlet for connection to an upstream portion of a plumbing system and an outlet for connection to a downstream portion of the plumbing system, a first check valve and a second check valve located in the body for preventing the reverse flow of water between the outlet and the inlet. An inlet pressure zone is positioned between the inlet and the first check valve, an outlet pressure zone is positioned between the outlet and the second check valve, and an intermediate pressure zone is positioned between the first and the second check valves. Position sensors sense the positions of the check valves, and pressure sensors sense the pressures in the zone. A controller in communication with the position sensors and the pressure sensors calculates the opening and closing pressures of the check valves.

A dialysis service box for centralized control and plumbing arrangement of a dialysis machine is disclosed. The dialysis service box includes a plumbing arrangement with a warm water inlet and a cold water inlet in fluid flow communication with a temperature mixing component. The thermostatic mixing component mixes the cold water and the warm water to produce mixed water maintained at a predetermined temperature between the temperature of the cold water and the temperature of the warm water. The dialysis service box can be universally installed to operate, control and adjust any dialysis machine that requires supply connection, waste connection, backflow preventer, thermostatic mixing component, a trap primer, or any combination of the foregoing.