Abstract: A backflow preventor which permits adjustment of the outflow direction is provided. A conduit provides fluid communication between the two valves of the backflow preventor. The conduit can be separated, e.g., by cutting along a groove, leaving annular flat regions. The annular flats are configured to engage with a coupler to provide leak-free connection between the separated portions of the conduit. The separated portions of the conduit can be rotated to adjust the outflow direction. Preferably, an infinite number of outflow directions are possible, all of which lie in a plane parallel to the inflow direction.

Abstract: Backflow prevention is provided in connection with a device having one or more shut-off valves integrated with a double-check-valve backflow prevention device and/or housing. Preferably, a single housing encompasses two backflow preventer check valves, and upstream and downstream shut-off valves. Typically, end users cannot readily remove the shut-off valves (and/or their housing) from the backflow preventer check valves (and/or their housing). No flange or other connection between shut-off valves and backflow preventer check valves (and/or their housing) is required, reducing size, weight and labor requirements. The system can substantially reduce or eliminate potential for installation of double-check-valve backflow preventer devices without shut-off valves.

Abstract: A backflow preventor which permits adjustment of the outflow direction is provided. A conduit provides fluid communication between the two valves of the backflow preventor. The conduit can be separated, e.g., by cutting along a groove, leaving annular flat regions. The annular flats are configured to engage with a coupler to provide leak-free connection between the separated portions of the conduit. The separated portions of the conduit can be rotated to adjust the outflow direction. Preferably, an infinite number of outflow directions are possible, all of which lie in a plane parallel to the inflow direction.

Abstract: Alignment and spacing apparatus for use in installing valves such as backflow preventer valves is provided. First and second couplers such as 90 degree elbow joints are each provided with alignment arms extending therefrom. The alignment arms have portions which permit the arms to be coupled to one another. The alignment arms provide for configuring the elbows in a predetermined relationship with one another, such as for providing for seating the alignment arms with respect to each other in a predetermined relationship. In one embodiment, each alignment arm has a flange portion which is seated against a shoulder portion of the other alignment arm in such a way that the elbow joints are connected such that the center line of the inlet and outlet of the elbow joints are substantially parallel and spaced apart a predetermined distance.

Abstract: A backflow preventor which permits adjustment of the outflow direction is provided. A conduit provides fluid communication between the two valves of the backflow preventor. The conduit can be separated, e.g., by cutting along a groove, leaving annular flat regions. The annular flats are configured to engage with a coupler to provide leak-free connection between the separated portions of the conduit. The separated portions of the conduit can be rotated to adjust the outflow direction. Preferably, an infinite number of outflow directions are possible, all of which lie in a plane parallel to the inflow direction.

Abstract: A backflow preventor which permits adjustment of the outflow direction is provided. A conduit provides fluid communication between the two valves of the backflow preventor. The conduit can be separated, e.g., by cutting along a groove, leaving annular flat regions. The annular flats are configured to engage with a coupler to provide leak-free connection between the separated portions of the conduit. The separated portions of the conduit can be rotated to adjust the outflow direction. Preferably, an infinite number of outflow directions are possible, all of which lie in a plane parallel to the inflow direction.

Abstract: A backflow preventor with increased performance, and increased ease of installation is provided. The check valves are configured to assist in redirecting flow along the desired pathway, when they are in the open position. The pathway is designed so that the number of changes of flow direction of the average streamline flow is reduced, preferably being about 180.degree.. The check valves are configured to reduce or eliminate divergent flow around the edges of the valve disks. A check valve with a reduced hold-open pressure includes a biasing device, such as a spring, directly connected to a pivoting clapper at one end and to the valve body at the other end. No intervening pivoting links are used between the spring and the clapper. Preferably, the clapper is connected only by being pivoted to the valve body and by the spring connecting it to the valve body.

Abstract: A backflow preventer assembly is provided, which allows for connection of the assembly to the variety of water line configurations. The valve device is attached to at least one rotatable, sealing flange which is rotatable from an in-line configuration to an L-shaped configuration. A rotating sealing flange is provided at each of the inlet opening and outlet opening of the valve device. A stop valve is positioned in each of the rotating flanges.

Abstract: A check valve with a reduced hold-open pressure includes a biasing device, such as a spring, directly connected to a pivoting clapper at one end and to the valve body at the other end. No intervening pivoting links are used between the spring and the clapper. Preferably, the clapper is connected only by being pivoted to the valve body and by the spring connecting it to the valve body.