In an exemplary embodiment, an emergency backflow preventing system is disclosed that includes an inflatable bladder, an air supply line demountably coupled to the inflatable bladder, a valve demountably coupled to the air supply line, and an air source functionally coupled to the valve. The inflatable bladder includes a deflated state and an inflated state and is substantially void of air in the deflated state. The inflatable bladder is configured to be inserted within a sewage pipe when in the deflated state. The inflatable bladder is configured to contact a bore of the sewage pipe when in the inflated state and thereby wedge itself within the sewage pipe. The inflatable bladder comprises an elastic polymer. The valve comprises a Schrader valve and an air pressure gauge. A cable is positioned within the air supply line and is anchored within the valve and the inflatable bladder.

A valve replacement device is disclosed. An example valve replacement device includes a body configured to thread onto a valve, and an insertion tube movable through the body. A seal is provided between the insertion tube and the body. The seal enables the insertion tube to be moved through the body while at least partially retaining a fluid within a portion of the body. A balloon is provided on the insertion tube. The balloon is configured to be inflated and deflated through the insertion tube. The balloon is inflated to retain a fluid within the tank while the existing valve is removed from the tank and replaced. The balloon is deflated and removed after replacement of the existing valve.

A valve replacement device is disclosed. An example valve replacement device includes a body configured to thread onto a valve, and an insertion tube movable through the body. A seal is provided between the insertion tube and the body. The seal enables the insertion tube to be moved through the body while at least partially retaining a fluid within a portion of the body. A balloon is provided on the insertion tube. The balloon is configured to be inflated and deflated through the insertion tube. The balloon is inflated to retain a fluid within the tank while the existing valve is removed from the tank and replaced. The balloon is deflated and removed after replacement of the existing valve.

An apparatus and associated method, for controlling signal passage, includes a first passageway for a first fluid, a second passageway for a second fluid, and an interposed chamber. A first, movable diaphragm at a first chamber junction and a second, movable diaphragm at a second chamber junction, with a third fluid bound there between and interposed between the first and second passageways. A device varies a volume of the third fluid bound between the diaphragms and thus moves the diaphragms. A movable member and a reservoir of the device are configured such that the movable member is sufficiently movable to increase the volume of the reservoir to remove a sufficient portion of the third fluid bound between the first and second diaphragms from the chamber to cause the first and second diaphragms to be pressed against the first and second walls, respectively.

An apparatus and associated method, for controlling signal passage, includes a first passageway for a first fluid, a second passageway for a second fluid, and an interposed chamber. A first, movable diaphragm at a first chamber junction and a second, movable diaphragm at a second chamber junction, with a third fluid bound there between and interposed between the first and second passageways. A device varies a volume of the third fluid bound between the diaphragms and thus moves the diaphragms. A movable member and a reservoir of the device are configured such that the movable member is sufficiently movable to increase the volume of the reservoir to remove a sufficient portion of the third fluid bound between the first and second diaphragms from the chamber to cause the first and second diaphragms to be pressed against the first and second walls, respectively.

Actuators having electroactive valves are described herein. The actuators can move from a first position to a second position and lock in the second position using an electroactive valve. The device can include an actuator having a fluid-impermeable membrane. The fluid-impermeable membrane can define a compartment, the compartment having a central region, an edge region extending from and fluidly connected with the central region, an electroactive valve between the central region and the edge region, and a dielectric fluid. When actuated, the actuators can force fluid through the electroactive valves and into the edge region. Once in the edge region, the electroactive valves can prevent return flow until receiving an actuation signal.

A flow restriction system for restricting fluid flow through a pipe includes an anchor and an inflatable plug. The anchor includes an alignment body, a shield body, and a first fluid passage defined in the alignment body and the shield body. The shield body extends from the alignment body and has an upstream face and a downstream face. The downstream face is opposite the upstream face. The shield body is configured to block at least a portion of the fluid flow through the pipe. The inflatable plug is coupled to the downstream face of the shield body. The inflatable plug includes an interior chamber that is in fluid communication with the first fluid passage.

A flow stopping tool for pipelines is disclosed, wherein the flow stopping tool comprises an inflatable balloon-like element that is in connection to a pressure rod. A hose is used for inflating the balloon-like element with a gas or a fluid, such that the balloon-like element can block a flow in a pipeline. A first end of the hose is in connection to the pressure rod and a second end of the hose is in connection to the balloon-like element. A part connecting the hose with the inflatable balloon-like element, but outside said balloon-like element, comprises a shock absorber for securing the hose-balloon connection.

A flow stopping tool for pipelines is disclosed, wherein the flow stopping tool comprises an inflatable balloon-like element that is in connection to a pressure rod, and a hinged coupling for securing the balloon-like element upon introduction into the pipeline, the hinged coupling comprising: a first element comprising a housing, a second element that is in connection to the balloon-like element; a buckling member connecting the first element to the second element, the buckling member being received in the housing of the first element. The buckling member comprises a cylinder that is configured to rotate around its longitudinal axis such that the second element can hinge with respect to the first element. The cylinder comprises at least one opening that facilitates measurement of the pressure of the flow in the pipeline, and the cylinder comprises at least one further opening that facilitates inflation of the balloon-like element.

A flow stopping tool for pipelines is disclosed, wherein the flow stopping tool comprises an inflatable balloon-like element that is in connection to a pressure rod, and a hinged coupling for securing the balloon-like element upon introduction into the pipeline, the hinged coupling comprising: a first element comprising a housing, a second element that is in connection to the balloon-like element; a buckling member connecting the first element to the second element, the buckling member being received in the housing of the first element. The buckling member comprises a cylinder that is configured to rotate around its longitudinal axis such that the second element can hinge with respect to the first element. The cylinder comprises at least one opening that facilitates measurement of the pressure of the flow in the pipeline, and the cylinder comprises at least one further opening that facilitates inflation of the balloon-like element.