Abstract: A leak detecting apparatus and method by which a regulated supply of gas is delivered from an adjustable pressure regulator to a smoke generator so that smoke generated within the smoke generator and carried to a fluid system being tested for leaks is at optimal density throughout the pressure range. The leak detecting apparatus and method have particular application for testing high pressure operating systems (e.g., the engine of a turbo-charged motor vehicle). A flow transducer measures the rate at which the regulated supply of gas flows to the smoke generator. First and second pressure transducers measure the pressure of the regulated gas and the pressure of the system being tested for leaks. The system under test is visually inspected for leaks after the pressure regulator is adjusted to a pressure to create an optimal maximum flow rate and the pressures measured by the first and second pressure transducers are equalized.

Abstract: An oil transporting vaporizer for a smoke generating apparatus to generate smoke to be supplied to a closed system to be tested for leaks. In a preferred embodiment, the vaporizer includes a hollow tube that is manufactured from a high temperature, fire resistant, porous material (e.g., ceramic). The vaporizer stands in a reservoir of oil such that some of the porous tube is filled with oil from the reservoir. A heater wire surrounds the outside of the porous tube above the oil within the tube. A gas (e.g., air) is blown into the porous tube and towards the oil to cause a mixture of air and gas to move through the tube. Because of its porosity, the air/oil mixture permeates the tube in the vicinity of the heater wire so as to be vaporized into smoke when the heater wire is energized.

Abstract: A portable, hand-held combination smoke machine and nitrogen generator having particular application for supplying a mixture of smoke and inert, non-combustible nitrogen gas to a closed fluid system (e.g., the evaporative or air brake system of a motor vehicle) so that the presence and location of a leak can be detected. The nitrogen generator is preferably a compact, commercially-available nitrogen generating membrane tube that is sized to be grasped and lifted in the hand of a user. The smoke machine has a smoke generator device that is adapted to produce smoke and is coupled to the nitrogen generating membrane tube so that a supply of nitrogen gas is delivered from the tube to the smoke generator device at which to be mixed with smoke. The nitrogen gas carries the smoke outwardly from the smoke generator device of the smoke machine to the system being tested for leaks.

Abstract: A filler neck insert to be removably attached to a capless fuel tank filler neck of a motor vehicle so that a source of pressure or a source of vacuum can be coupled to the fuel tank in order to test the fuel tank for leaks. The filler neck insert includes a hollow tubular body to be received through the open fuel-mouth and suspended within the throat of the fuel tank filler neck and a base extending across the tubular body. An adapter which is connected to the filler neck insert has an outer rim mated in surrounding sealing engagement with the base of the insert and an inlet tube connected to the source of pressure or vacuum. Accordingly, a flow path is established from the pressure or vacuum source to the fuel tank by way of the adapter, the insert and the filler neck.

Abstract: A filler neck adapter to be inserted through the open fuel mouth of a capless filler neck of a fuel tank of a motor vehicle. The adapter has a hollow flow body to create a continuous flow path between a source of pressure or vacuum and the fuel tank to enable the fuel tank to be tested for leaks. A resilient seal surrounds the flow body of the adapter so as to lie between movable and stationary seal stops. A force-generating member is moved along the flow body to push the movable seal stop and the seal towards the stationary seal stop. Accordingly, the seal is compressed between the movable and stationary seal stops so as to bulge outwardly towards and thereby create an air-tight seal against the fuel mouth of the filler neck.

Abstract: A universal adapter to be detachably connected to the round fuel cap retaining lip of most any fuel tank filler neck so that smoke (i.e., a vapor) under pressure can be delivered to the fuel tank of a motor vehicle to test the fuel system for leaks. When connected, the universal adapter lies entirely outside the fuel tank filler neck. The universal adapter includes a circular ring-shaped rim that is manufactured from a flexible material having a spring memory. The flexible rim of the universal adapter is stretched and attached in surrounding sealing engagement against the fuel cap retaining lip of the filler neck. The universal adapter also includes a vapor inlet tube to which the nozzle of a vapor supply hose is attached. According to one embodiment, smoke produced by a smoke-generating machine pressurizes the fuel tank by way of a vapor delivery path which includes the vapor inlet tube of the universal adapter and the fuel tank filler neck of the motor vehicle.

Abstract: A compact (e.g., hand held) vacuum generator having particular application for creating a vacuum within the evaporative emissions system (e.g., a gas tank) of a motor vehicle so that a vacuum-decay test can be performed to test the system for leaks while mitigating the hazardous effects of potentially explosive hydrocarbon vapors. The vacuum generator includes a spool valve that has an internal passage and is capable of sliding through a spool valve bore in response to a pushing force. During an at-rest stage of the spool valve within the spool valve bore, the system to be tested is disconnected from the vacuum generator. During a transition stage of the spool valve within the spool valve bore, inlet gas under pressure is blown through the internal passage of the spool valve to the atmosphere by way of a vacuum generating venturi, whereby a vacuum begins to form in a vacuum passage.

Abstract: A smoke and clean air generating machine for detecting the presence and location of leaks in a fluid system (e.g. the evaporative or brake system of a motor vehicle). A source of gas (e.g. air or nitrogen) under pressure is delivered to a smoke generating apparatus or to a flow meter by way of a multi-position selector valve. With the selector valve in a first position, gas is delivered to the system under test via the flowmeter to detect the presence of a leak in need of repair depending upon the reading of the flow meter. With the selector valve in a second position, gas is delivered to the smoke generating apparatus so that smoke can be supplied to the system under test to locate the leak. With the selector valve in a third position between the first and second positions, pressure is bled from the machine to disable the smoke generating apparatus and thereby terminate the production of smoke.

Abstract: A method for detecting leaks in a fluid system such as, but not limited to, the evaporative or air brake system of a motor vehicle. A smoke generating machine produces a supply of smoke to be delivered to the system under test. At least some of a mixture of oil and fluorescent dye is heated and vaporized into smoke within a sealed chamber. The smoke functions as a carrier for the dye. Some of the smoke which is delivered to the system under test from the chamber will exit a leak (e.g. a hole), and the fluorescent dye carried by the smoke will leave a fluorescent trace around the leak. By shining ultraviolet light along the system under test, the fluorescent trace around the leak will be illuminated. Accordingly, even small leaks may be quickly, easily and reliably located for repair.

Abstract: A liquid for producing a marker vapor includes a fluorescent substance in solution in a carrier liquid. The fluorescent substance has a first vaporization temperature range at which the fluorescent substance vaporizes. The carrier liquid has a second vaporization temperature range at which the carrier liquid vaporizes. The second vaporization temperature range overlaps the first vaporization range. The liquid is vaporized and directed into a body being inspected. Leaks then become visible when the body is inspected using radiation of a wavelength that causes the fluorescent substance to fluoresce.

Abstract: A smoke generating apparatus includes a combustion chamber having an air flow inlet and an air flow outlet. A helical heating element is disposed in the combustion chamber. The helical heating element has a central flow axis. A smoke generating fluid injection tube is positioned along the central flow axis of the helical heating element.