Abstract: A pumping apparatus comprises a rotatable shaft coupled to a motor. At least one control structure is mounted on the shaft, and at least one impeller is carried by the shaft. The impeller is adapted to rotate independently of the shaft so as to pump a fluid. The apparatus also comprises a magnetic coupling between the control structure and the impeller. Further, the impeller is adapted to translate axially along the shaft in response to a change in downstream pressure to alter the strength of the magnetic coupling.

Abstract: A pumping apparatus comprises a rotatable shaft coupled to a motor. At least one control structure is mounted on the shaft, and at least one impeller is carried by the shaft. The impeller is adapted to rotate independently of the shaft so as to pump a fluid. The apparatus also comprises a magnetic coupling between the control structure and the impeller. Further, the impeller is adapted to translate axially along the shaft in response to a change in downstream pressure to alter the strength of the magnetic coupling.

Abstract: An in-dispenser leak pan provided inside the housing of a fuel dispenser. The leak collection chamber collects any fuel that leaks from fuel-handling components located inside the fuel dispenser above the pan. The pan is secondarily contained by an outer pan or container such that an interstitial space is formed therebetween. If a breach exists in the top part of the pan, the captured leaked fuel will be contained in by the outer pan in the interstitial space. The interstitial space of the pan is drawn under a vacuum level using a vacuum-generating source to monitor for leaks. If a leak is detected, a control system may generate an alarm and/or cause the submersible turbine pump to stop supplying fuel, or cause the dispenser product line shear valves to close, thereby only stopping fuel flow to the individual fuel dispenser containing the leak.

Abstract: An end-of-zone or line sensor placed at the end of a secondarily contained fuel piping(s) or network(s). The interstitial space of the piping network is coupled to a vacuum-generating source that draws a vacuum level in the interstitial space to monitor for leaks or breaches in the piping network. The end-of-zone sensors are coupled to the interstitial space at the far end of the piping network and vacuum-generating source. The end-of-zone sensors actuate when a sufficient vacuum level is detected. A control system monitors the status of the end-of-zone switches. If the vacuum-generating source is activated to draw a vacuum level, and the end-of-zone sensors react to indicate the vacuum level has reached the sensor, the control system knows that there is no blockage over the entire span of the piping network, and thus entire piping network can be properly monitored for leaks.

Abstract: A redundant vacuum-generating source system and method for generating and/or maintaining a vacuum level in a secondarily contained fuel-handling component that is monitored for leaks. The vacuum-generating source is coupled to upstream fuel-handling components to draw a vacuum level in their interstitial spaces. Other downstream fuel-handling components are drawn under a vacuum by tapping off of the upstream fuel-handling component's interstitial spaces for convenience. A series of valves control which upstream fuel-handling component's interstitial spaces are coupled to a downstream fuel-handling component interstitial space. In the event that an upstream fuel-handling component contains a leak, a control system can control the valves to switch the vacuum generation of a downstream fuel-handling component to another upstream fuel-handling component that does not contain a leak so that a sufficient vacuum level can be generated in downstream fuel-handling component(s) to monitor it for leaks.