Automatic pressure-adjusting leak detecting apparatus and method

A leak detecting apparatus to indicate the presence of a leak in a fluid system that is coupled to said apparatus, said leak testing apparatus comprising:

• a gas inlet to receive a gas;
• an adjustable pressure regulator coupled to said gas inlet to provide a pressure regulated supply of the gas received from said gas inlet;
• an inlet gas pressure-responsive switch lying between said gas inlet and said adjustable pressure regulator and being responsive to the pressure of the gas received by said gas inlet;
• a smoke generator to produce visible smoke, said smoke generator communicating with the fluid system to be tested for leaks;
• a gas flow path extending between said pressure regulator and said smoke generator so that the pressure regulated supply of gas is delivered to the smoke generator to carry the smoke produced by said generator to the system under test whereby said system is pressurized;
• a flow transducer lying within said gas flow path to measure the rate at which the pressure regulated supply of gas flows therethrough from said pressure regulator to said smoke generator;
• a controller to adjust the adjustable pressure regulator until the pressure of the pressure regulated supply of gas provided by said pressure regulator and the pressure of the system under test are equalized so as to cause the flow rate measured by said flow transducer to be reduced at which time the system under test is inspected for leaks, said controller being electrically connected to said inlet gas pressure-responsive switch to receive a signal from said switch and thereby cause said switch to permit the gas to flow from said gas inlet to said adjustable pressure regulator when the gas has at least a certain pre-determined pressure so that the adjustable pressure regulator can then be adjusted by said controller;
• and
• a motor connected between said controller and said adjustable pressure regulator, said controller operating said motor and said motor correspondingly adjusting said pressure regulator until the pressure of the regulated supply of gas provided by said pressure regulator and the pressure of the system under test have been equalized.

A method for testing a fluid system for leaks, said method comprising the steps of:

• connecting the system under test so as to lie in fluid communication with a smoke generating chamber;
• generating smoke within said smoke generating chamber;
• supplying from a source thereof a regulated gas having an adjustable pressure to said smoke generating chamber to carry the smoke from said chamber to the system being tested for leaks whereby to pressurize said system;
• measuring the pressure of said regulated gas by means of a first pressure transducer communicating with said source of regulated gas;
• measuring the pressure of the system under test by means of a second pressure transducer communicating with said smoke generating chamber;
• and
• comparing the pressures measured by said first and second pressure transducers and adjusting the pressure of said regulated gas until the pressure of said regulated gas and the pressure of the system under test are equalized;
• and
• visually inspecting the system under test by identifying smoke which exits any leak site in the system when the pressures of said regulated gas and said system are equalized.