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 double check valve reduced pressure backflow preventor assembly is configured to have a relatively small length, volume and/or weight. The assembly defines parallel, preferably coaxial, inlet and outlet directions. In one aspect, first and second check valves are at an angle, preferably of 90°, to the in-line axis and preferably intersect the in-line axis. In one aspect, a relief valve is positioned spaced from the in-line axis. First and second shutoff valves are enclosed in the same integral, unitary housing which encloses the check valves and, preferably, some or all of the relief valve. The shutoff valves are preferably positioned along the in-line axis.

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 double check valve reduced pressure backflow preventor assembly is configured to have a relatively small length, volume and/or weight. The assembly defines parallel, preferably coaxial, inlet and outlet directions. In one aspect, first and second check valves are at an angle, preferably of 90°, to the in-line axis and preferably intersect the in-line axis. In one aspect, a relief valve is positioned spaced from the in-line axis. First and second shutoff valves are enclosed in the same integral, unitary housing which encloses the check valves and, preferably, some or all of the relief valve. The shutoff valves are preferably positioned along the in-line axis.

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: 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 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.