A backflow preventer adapted for installation in an inner conduit of a hose coupling of a hydrant is disclosed. The backflow preventer contains a non-return device having a closing body, a seal seat, and a resetting device. The resetting device is adapted to resiliently pretension the closing body into sealing engagement against the seal seat.

A backflow preventer adapted for installation in an inner conduit of a hose coupling of a hydrant is disclosed. The backflow preventer contains a non-return device having a closing body, a seal seat, and a resetting device. The resetting device is adapted to resiliently pretension the closing body into sealing engagement against the seal seat.

There is provided a system separator having a backflow preventer including a housing enclosing a main flow conduit, a valve seat inside the housing on the main flow conduit, and a valve body movable relative to the valve seat to close off the main flow conduit together with the valve seat in a closed position and to release the main flow conduit in an open position. The valve body is alternately movable between the closed position and the open position by at least one of a pressure difference in the main flow conduit or a force of a spring element, and the main flow conduit is divided in the area of the valve body into at least one outer flow conduit and one inner flow conduit, and the valve body encloses the inner flow conduit and forms at least one valve-body valve seat on the inner flow conduit.

There is provided a system separator having a backflow preventer including a housing enclosing a main flow conduit, a valve seat inside the housing on the main flow conduit, and a valve body movable relative to the valve seat to close off the main flow conduit together with the valve seat in a closed position and to release the main flow conduit in an open position. The valve body is alternately movable between the closed position and the open position by at least one of a pressure difference in the main flow conduit or a force of a spring element, and the main flow conduit is divided in the area of the valve body into at least one outer flow conduit and one inner flow conduit, and the valve body encloses the inner flow conduit and forms at least one valve-body valve seat on the inner flow conduit.

A system and method are disclosed for shutting off the flow of liquid to a hydrant. A break away frangible activator of a valve body becomes dislodged responsive to a hydrant receiving sufficient inadvertent impact. A valve member closes in response to the impact to close off the flow of fluid to the hydrant.

A system and method are disclosed for shutting off the flow of liquid to a hydrant. A break away frangible activator of a valve body becomes dislodged responsive to a hydrant receiving sufficient inadvertent impact. A valve member closes in response to the impact to close off the flow of fluid to the hydrant.

A system and method are disclosed for shutting off the flow of liquid to a hydrant. A break away frangible activator of a valve body becomes dislodged responsive to a hydrant receiving sufficient inadvertent impact. A valve member closes in response to the impact to close off the flow of fluid to the hydrant.

A system and method are disclosed for shutting off the flow of liquid to a hydrant. A break away frangible activator of a valve body becomes dislodged responsive to a hydrant receiving sufficient inadvertent impact. A valve member closes in response to the impact to close off the flow of fluid to the hydrant.

An insertable backflow preventer is presented. The backflow preventer is provided with a cylindrical housing. The housing has a flow transition zone, a proximal orifice/ball seat, a ball with a specific weight that equals or is close to the specific weight of the surrounding fluid, and a distal retaining screen. The housing can have a flange provided on the outside of the housing at one end to facilitate securing the valve in a pipe. The valve is self-cleaning, can be placed in any orientation in a pipe and has low hydraulic head-loss. The valve's unique cost-effective design provides for easy and relative quick installation, eliminates the need to reconfigure existing plumbing, and can be performance tested remotely. Properly installed, it can dramatically improve the security of, for example, potable water sources in a building or other context, and inasmuch as when installed it is not visible, it is tamper proof. The valve can be scaled to any size pipe or tube, and due to its internal flow dynamics is self cleaning. Multiple valves can be installed in series, and balls of varying specific weight can be used in each valve in such a series to allow for contexts where a range of fluids are sent through the same line, or to provide fail-safe operation in the event that contaminants change the specific gravity of the fluid.

An insertable backflow preventer is presented. The backflow preventer is provided with a cylindrical housing. The housing has a flow transition zone, a proximal orifice/ball seat, a ball with a specific weight that equals or is close to the specific weight of the surrounding fluid, and a distal retaining screen. The housing can have a flange provided on the outside of the housing at one end to facilitate securing the valve in a pipe. The valve is self-cleaning, can be placed in any orientation in a pipe and has low hydraulic head-loss. The valve's unique cost-effective design provides for easy and relative quick installation, eliminates the need to reconfigure existing plumbing, and can be performance tested remotely. Properly installed, it can dramatically improve the security of, for example, potable water sources in a building or other context, and inasmuch as when installed it is not visible, it is tamper proof. The valve can be scaled to any size pipe or tube, and due to its internal flow dynamics is self cleaning. Multiple valves can be installed in series, and balls of varying specific weight can be used in each valve in such a series to allow for contexts where a range of fluids are sent through the same line, or to provide fail-safe operation in the event that contaminants change the specific gravity of the fluid.