A sealing tightness measuring device and a pressure-retaining capability measuring gauge for a pressure container or system is provided. A pressure is produced against the testing fluid inside a piston cylinder communicated with the tested container or system by an assembly including a weight, a piston, and a piston cylinder successively arranged through a coaxial plumb bob. An equation R.sub.L=pt/C is used to represent the sealing tightness of the pressure container or system. The equation pt=p(p0.5p)t/p is used in the pressure-retaining capability measuring gauge to express the pressure-retaining capability, wherein p is the fixed testing fluid pressure, t is the elapsed time for the fluid to leak completely, C is the volume of the pressure container or system, p is the drop value of the pressure, and t is the elapsed time for the pressure to descend from p to (pp) caused by the leakage.

A method is disclosed herein for detecting cracks of a fluid storage tank due to breakage of a wall of the fluid storage tank. In an example embodiment, the method includes positioning an enclosed pressure-resistant jacket around an outer wall of the fluid storage tank, controlling a temperature of the fluid in the fluid storage tank by allowing a liquid cooling or heating medium to flow in the enclosed pressure-resistant jacket at a pressure lower than a pressure x applied within the fluid storage tank, maintaining the pressure in the pressure-resistant jacket lower than the pressure x, sampling the cooling or heating medium from an air pool provided in a passage of the cooling or heating medium, and analyzing components of the cooling or heating medium, while preventing contamination of the fluid in the fluid storage tank with the liquid cooling or heating medium.

A method is disclosed herein for detecting cracks of a fluid storage tank due to breakage of a wall of the fluid storage tank. In an example embodiment, the method includes positioning an enclosed pressure-resistant jacket around an outer wall of the fluid storage tank, controlling a temperature of the fluid in the fluid storage tank by allowing a liquid cooling or heating medium to flow in the enclosed pressure-resistant jacket at a pressure lower than a pressure x applied within the fluid storage tank, maintaining the pressure in the pressure-resistant jacket lower than the pressure x, sampling the cooling or heating medium from an air pool provided in a passage of the cooling or heating medium, and analyzing components of the cooling or heating medium, while preventing contamination of the fluid in the fluid storage tank with the liquid cooling or heating medium.

A composite structure of a cargo body and a method of making the same are disclosed. The composite structure includes at least one electrical grid embedded within fiber-reinforced polymer (FRP) layers. The embedded electrical grid includes a plurality of conductive fibers and a plurality of insulating fibers integrated into a polymer matrix of the FRP layers. The embedded electrical grid may be used for power distribution, structural strengthening and stiffness, and/or puncture detection.

Systems, methods and apparatuses for inspecting a tank containing a flammable fluid are provided. The system includes a vehicle having a propeller, a latch mechanism, a pressure switch, and an inspection device. The system includes a control unit in communication with the propeller, the latch mechanism, and the inspection device, and electrically connected to the pressure switch. The control unit powers on responsive to the pressure switch detecting an ambient pressure greater than a minimum threshold. The control unit receives, from the latch mechanism, an indication of a state of the latch mechanism. The control unit determines that the cable used to lower the vehicle into the tank containing the flammable fluid is detached from the vehicle. The control unit commands the propeller to move the vehicle through the flammable fluid. The control unit determines a quality metric of a portion of the tank.

Systems, methods and apparatuses for inspecting a tank containing a flammable fluid are provided. The system includes a vehicle having a propeller, a latch mechanism, a pressure switch, and an inspection device. The system includes a control unit in communication with the propeller, the latch mechanism, and the inspection device, and electrically connected to the pressure switch. The control unit powers on responsive to the pressure switch detecting an ambient pressure greater than a minimum threshold. The control unit receives, from the latch mechanism, an indication of a state of the latch mechanism. The control unit determines that the cable used to lower the vehicle into the tank containing the flammable fluid is detached from the vehicle. The control unit commands the propeller to move the vehicle through the flammable fluid. The control unit determines a quality metric of a portion of the tank.

A spill containment system is attachable to a riser pipe with an axially moveable seal. The spill containment system allows access to a drop tube in the riser pipe via a removable liquid communication assembly. The spill containment system includes a sealed interstitial space, which remains sealed during installation, service and use of the system. The spill containment system is protected by a weather resistant cover assembly.

A method is disclosed herein for preventing contamination of a fluid in a fluid storage tank with a liquid cooling or heating medium due to breakage of a wall of the fluid storage tank. In an example embodiment, the method includes positioning an enclosed pressure-resistant jacket around an outer wall of the fluid storage tank, controlling a temperature of the fluid in the fluid storage tank by allowing the liquid cooling or heating medium to flow in the enclosed pressure-resistant jacket at a pressure lower than a pressure x (atm) applied within the fluid storage tank, and maintaining the pressure in the pressure-resistant jacket lower than the pressure x.

A method is disclosed herein for preventing contamination of a fluid in a fluid storage tank with a liquid cooling or heating medium due to breakage of a wall of the fluid storage tank. In an example embodiment, the method includes positioning an enclosed pressure-resistant jacket around an outer wall of the fluid storage tank, controlling a temperature of the fluid in the fluid storage tank by allowing the liquid cooling or heating medium to flow in the enclosed pressure-resistant jacket at a pressure lower than a pressure x (atm) applied within the fluid storage tank, and maintaining the pressure in the pressure-resistant jacket lower than the pressure x.

A fluid retaining structure comprising an electronic leak detection and location, ELDL, system, wherein the fluid retaining structure comprises inner and outer liners (18, 16) that form electrical isolation layers of the ELDL system, wherein an electrically conductive signal layer (10, 12) of the ELDL system provides structural rigidity to the fluid retaining structure.