Patent ID: 8104327

Claim:
A method for detecting a potential leak in a primary vessel, the method also determining if there is a leak, a location of the leak in the primary vessel, the method using a gas leak detector with gas sensor and a computer, the computer attached to the gas leak detector, the primary vessel made from a known material, the method comprising: introducing a tracer gas under pressure inside a first test vessel, the first test vessel made of the same material as the primary vessel's known material, the first test vessel disposed inside a second test vessel with an annular space therebetween; sampling periodic measurements of the tracer gas permeating through the first test vessel into the annular space over a period of time and using air flow through the annular space to the gas leak detector; uploading the periodic measurements as electronic signals to the computer and creating a standard permeability curve using the periodic measurements, the standard permeability curve used in detecting for the potential leak in the primary vessel, the standard permeability curve having a test standard to determine if the primary vessel should be taken out of service for repair due to excessive leakage and exceeding the test standard; in the field, introducing the tracer gas under pressure inside the primary vessel, the primary vessel disposed inside a secondary vessel with an annular space therebetween; sampling periodic measurements of the tracer gas permeating through the primary vessel into the annular space using air flow through the annular space to the gas leak detector; uploading the periodic measurements as electronic signals to the computer and creating a primary vessel test curve using the periodic measurements; comparing the primary vessel test curve on the computer with the standard permeability curve on the computer to determine if the test curve exceeds the standard set by the permeability curve for leakage through the vessel's known material; testing further the primary vessel in the field if the test curve exceeds the test standard set by the standard permeability curve; measuring the time between a trough and a crest of a wave in a wave cycle on the test curve; determining the volume in the annular space between the primary and secondary vessels; determining the length of the annular space between the primary vessel and the secondary vessel; determining the air flow volume per time of the air flow through the annular space between the primary and secondary vessels; dividing the volume in the annular space by the length of the annular space to determine a square area under test, dividing the square area under test by the air flow volume to determine the velocity of the air flow in the annular space; and multiplying the air flow velocity times the time between the trough and the crest of the wave to determine the distance to the leak in the primary vessel from the gas leak detector.