A method for controlling charge accumulation on a mobile platform in a tank containing a non-conductive, energetic substance includes configuring the mobile platform to include at least an electrical power supply and a charge accumulation control system. The power supplied from the electrical power supply to one or more electrical power consumers associated with the mobile platform adds an electrical charge to the mobile platform. The charge accumulation control system controls an accumulation of the electrical charge on the mobile platform by one of: (i) reducing the supplied power and preventing an increase in the supplied power later while the mobile platform is inside the tank, and (ii) disengaging the electrical power consumer(s) from the supplied power and preventing a reengagement of the supplied power with the electrical power consumer(s) later while the mobile platform is inside the tank.

Methods for quantitatively determining the time (TNI) between (1) the application of this method and (2) the time at which the next out-of-service API 653 internal inspection of a steel, field-erected, aboveground storage tank (AST) containing petroleum/water products should be performed. These methods combine four in-service measurements of the thickness, integrity, and corrosion rate of the tank bottom with an empirical corrosion rate cumulative frequency distribution (CFD) for the tank of interest to develop a Bayesian tank bottom survival probability distribution to determine TNI. During this entire TNI time period, the risk of tank bottom failure is less than at the time these methods were applied. If available, the results of a previous out-of-service API 653 internal inspection are also used. These methods can be applied at any time while the tank is in-service to update the internal inspection interval previously determined in an out-of-service internal inspection of the tank.

A method of performing a selected task in a tank at least partially filled with an energetic substance includes, in part, configuring a mobile platform to be inherently safe by positioning spark-generating components in either or both of: (i) an inherently safe enclosure that prevents a spark occurring inside the inherently safe enclosure from passing to an exterior of the inherently safe enclosure, and (ii) a spark-neutralizing body formed of at least one non-flammable substance and positioned inside an enclosure, the spark-neutralizing body blocking direct contact between a spark from the enclosed spark-generating component and an energetic substance from occurring inside the at least one enclosure. The method also includes positioning at least one spark-generating component not inside any inherently safe enclosure that prevents a spark occurring inside the inherently safe enclosure from passing to an exterior of the inherently safe enclosure. The sparks are capable of igniting the energetic substances.

A high-pressure tank is detected to rupture before the rupture of the tank with high accuracy. The pressure when the indicator obtained based on measured acoustic emission or sound is at least a threshold value is defined as a pressure just before a rupture.

A method of retrieving a mobile platform from a tank having a hatch and at least partially filled with a non-conductive, energetic substance includes configuring the mobile platform to include at least a retrieval system disposed at least partially on an enclosure. The retrieval system includes at least: a primary tether connected to a buoyant body and to the enclosure, and a secondary tether connected to the buoyant body and to the enclosure. The method further includes: predetermining a buoyant body retrieval zone within the tank, and positioning a released buoyant body within the buoyant body retrieval zone by using the primary tether. The method also includes retrieving the primary tether by using the buoyant body; using the primary tether to release the secondary tether; and inserting a retrieval member through the hatch to retrieve the buoyant body, the primary tether, and/or the secondary tether.

The disclosed technology can include a system for monitoring and detecting a fault in a fluid storage tank. A sensor can be located in, on, or proximate the fluid storage tank and can be configured to detect waveforms produced by the fluid storage tank in response to strain. The sensor can convert such waveforms into electrical signals and transmit such electrical signals in the form of vibration data to a controller. The controller can compare the vibration data to stored data, and based on such comparison, determine if a fault is present in the fluid storage tank.

A method and apparatuses to extend the time interval between out-of-service, in-tank inspections while insuring structural integrity using a risk-based, Bayesian statistical approach comprised of a passing leak detection test and the using the results from (1) tank floor thickness measurements, (2) prior out-of-service tank floor inspection results, and/or (3) acoustic emission corrosion maps of the tank floor to estimate the minimum thickness and maximum corrosion rate of the tank during the extension period. The present invention uses an in-tank, mass-based leak detection system to establish tank integrity, three or more ultrasonic (UT) thickness measurement sensors for measurements of the tank floor at one location, and to establish the spatial distribution of corrosion of the tank floor, one or more prior API 653/12R1 or STI SP001 tank floor thickness inspections and/or three or more in-tank AE sensors mounted inside the tank with vertical and horizontal locations in an oblique plane relative to the tank floor.

Embodiments of the present invention provide systems and methods for tagging and acoustically characterizing containers.

A life estimation apparatus for a pressure accumulator estimates the life of the pressure accumulator based on an AE signal for the pressure accumulator. The life estimation apparatus includes: an AE sensor that is provided at the pressure accumulator and detects the AE signal; and an estimation unit that sets a point of time at which the AE sensor detects a damage AE signal that is generated from the pressure accumulator because of damage of a material during use of the pressure accumulator, as a minimum initial flaw generation time point that is a point of time at which a minimum initial flaw of the pressure accumulator that is detected by a non-destructive inspection method is generated in shipping of the pressure accumulator.

A pressure testing method capable of determining with a higher accuracy whether a high-pressure tank is deteriorated. The pressure testing method tests the high-pressure tank that includes a liner and a fiber-reinforced resin layer covering the outer surface of the liner and that has been used while repeating charge and discharge of gas to and from the inside thereof after undergoing a pressure resistance test conducted at a pressure resistance test pressure. The method increases the internal pressure of the high-pressure tank filled with gas to a test pressure that is lower than the pressure resistance test pressure, so that a plurality of AE waveforms is extracted from output waveforms of an AE sensor that detects AE waves generated in the high-pressure tank, and determines whether the high-pressure tank is deteriorated, on the basis of the extracted AE waveforms.