Abstract: A double-walled shear valve that carries fuel from a branch or main fuel piping to fuel dispenser piping. The double-walled shear valve comprises a containment housing defining a shear groove on the outside circumference of the containment housing and an inner housing defining an inner housing orifice therein forming a fuel flow path. The inner housing is coupled to the containment housing, and at least partially surrounded by the containment housing, such that an interstitial space is formed separate from the fuel flow path between the containment housing and the inner housing. The double-walled shear valve further comprises a main poppet valve coupled to the inner housing that is adapted to close the fuel flow path to prevent flow of fuel.

Abstract: A vacuum-actuated shear valve coupled between piping from a storage tank and piping internal to a fuel dispenser that automatically opens and closes in response to a vacuum level. A vacuum actuator is provided to control a fuel flow valve inside the shear valve. When a sufficient vacuum level is generated to the vacuum actuator, the actuator keeps the flow path valve inside the shear valve open. When the vacuum is lost, the vacuum actuator releases the flow path valve inside the shear valve, which closes it. The vacuum actuator is coupled to a secondary containment space of a fuel-handling component that is drawn under a vacuum level by a vacuum-generating source to monitor for leaks. Thus, if a leak occurs in the monitored secondarily contained space, the shear valve is automatically closed to prevent the flow of fuel from continuing to be supplied to the source of the leak.

Abstract: A double-walled shear valve that carries fuel from a branch or main fuel piping to fuel dispenser piping. The double-walled shear valve comprises a containment housing defining a shear groove on the outside circumference of the containment housing and an inner housing defining an inner housing orifice therein forming a fuel flow path. The inner housing is coupled to the containment housing, and at least partially surrounded by the containment housing, such that an interstitial space is formed separate from the fuel flow path between the containment housing and the inner housing. The double-walled shear valve further comprises a main poppet valve coupled to the inner housing that is adapted to close the fuel flow path to prevent flow of fuel.

Abstract: A vacuum-actuated shear valve coupled between piping from a storage tank and piping internal to a fuel dispenser that automatically opens and closes in response to a vacuum level. A vacuum actuator is provided to control a fuel flow valve inside the shear valve. When a sufficient vacuum level is generated to the vacuum actuator, the actuator keeps the flow path valve inside the shear valve open. When the vacuum is lost, the vacuum actuator releases the flow path valve inside the shear valve, which closes it. The vacuum actuator is coupled to a secondary containment space of a fuel-handling component that is drawn under a vacuum level by a vacuum-generating source to monitor for leaks. Thus, if a leak occurs in the monitored secondarily contained space, the shear valve is automatically closed to prevent the flow of fuel from continuing to be supplied to the source of the leak.

Abstract: A double-walled contained shear valve comprises of an inner housing forming a fuel flow path, and a containment housing surrounding the inner housing, either partially or wholly, to provide a secondary containment. An interstitial space is formed between the inner housing and the containment housing as a result, and may be placed under a vacuum or pressure level to monitor for leaks. A vacuum actuator coupled to the interstitial space automatically opens and closes the fuel flow path of the shear valve in response to the vacuum level in the interstitial space to prevent leaks to the environment. The shear valve may contain a flange for connection to internal fuel dispenser piping that either does or does not includes interstitial space orifices to couple the shear valve interstitial space to the fuel dispenser piping interstitial space to monitor the vacuum or pressure level in these interstitial spaces as one contiguous space.

Abstract: A vacuum-actuated shear valve coupled between piping from a storage tank and piping internal to a fuel dispenser that automatically opens and closes in response to a vacuum level. A vacuum actuator is provided to control a fuel flow valve inside the shear valve. When a sufficient vacuum level is generated to the vacuum actuator, the actuator keeps the flow path valve inside the shear valve open. When the vacuum is lost, the vacuum actuator releases the flow path valve inside the shear valve, which closes it. The vacuum actuator is coupled to a secondary containment space of a fuel-handling component that is drawn under a vacuum level by a vacuum-generating source to monitor for leaks. Thus, if a leak occurs in the monitored secondarily contained space, the shear valve is automatically closed to prevent the flow of fuel from continuing to be supplied to the source of the leak.

Abstract: A shear valve employing a two-stage main poppet valve. The two-stage main poppet valve that can be opened with less force than normally required by prior art designs. For example, if there is pump pressure trapped on the upstream side of the two-stage main poppet valve and little or no pressure or atmospheric pressure on the downstream side, more force than can be provided may be required to open the two-stage main poppet valve to reset the shear valve after the two-stage main poppet valve is closed. The two-stage main poppet valve is designed to first begin to equalize pressure differential across the shear valve without opening a main poppet valve head from its seat inside the shear valve. Thereafter, the main poppet valve head can be opened with less force than otherwise would be required.

Abstract: A double-walled contained shear valve comprises of an inner housing forming a fuel flow path, and a containment housing surrounding the inner housing, either partially or wholly, to provide a secondary containment. An interstitial space is formed between the inner housing and the containment housing as a result, and may be placed under a vacuum or pressure level to monitor for leaks. A vacuum actuator coupled to the interstitial space automatically opens and closes the fuel flow path of the shear valve in response to the vacuum level in the interstitial space to prevent leaks to the environment. The shear valve may contain a flange for connection to internal fuel dispenser piping that either does or does not includes interstitial space orifices to couple the shear valve interstitial space to the fuel dispenser piping interstitial space to monitor the vacuum or pressure level in these interstitial spaces as one contiguous space.

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.

Abstract: A closed loop control system for a pneumatic actuator using position and pressure feedback signals. The feedback signals are supplied to a microprocessor which successively generates a desired acceleration, a desired actuator force, a desired gas pressure, and a gas mass flow rate command for a gas flow controlling valve. The use of the gas flow rate as a control variable decouples pneumatic ronlinearities from the control loop. Nonlinear viscous friction, coulomb friction and load effects are decoupled from the control loop prior to the calculation of the desired pressure. An improved trajectory is achieved by employing a plurality of trajectory phases, including a velocity control phase.

Abstract: An impact damping element is provided including an annular bumper portion and a seal portion surrounding the bumper portion for engaging an inner wall of a cylinder in sealing contact. The impact damping element is adapted to absorb the impact between a piston and the end of a cylinder wall. In one embodiment of the invention, a primary and a secondary bumper are provided wherein the primary bumper has a greater height than the secondary bumper such that the primary bumper absorbs an initial impact between the piston and the cylinder wall and the secondary bumper absorbs the remaining force to prevent direct contact between the piston and the cylinder wall.

Abstract: A pressure control valve and transducer package for use in combination with a pneumatic actuator which incorporates a double acting pneumatic cylinder includes, in a single multi-component unit, a valve assembly constructed for direct coupling into the pneumatic pressure loop for operating the actuator, and a second component which comprises a fixture housing one or more continuously operating sensors for measuring the pressures supplied to the opposite ends of the cylinder in the actuator and transmitting appropriate signals conveying that information to a microprocessor which in turn regulates the supply flow rate of pressure gas to the cylinder through a closed loop feedback system.