Abstract: The semi-permeable characteristics of polymeric liners may be used to characterize defects, if present, in loose liners contained inside piping and equipment. The use of polymer-lined equipment is common in the chemical, refining and other industries where the polymeric liner offers excellent chemical resistance and the outer shell gives the required strength and rigidity. Permeability characteristics of liners are investigated with particular reference to volatile process gasses and/or process-soluble tracer gasses. The resulting data are used to establish nondestructive testing techniques for evaluating the integrity of lined equipment during normal operation where a mass spectrometer equipped with a sampling probe is used as the sampling and sensing devices. Real-time data is compared to characteristic data, obtained under laboratory conditions, on a membrane of the polymer from which the liners are made. Acceptance or rejection of the equipment is determined by such comparison.

Abstract: The invention comprises a tool which can be inserted through the fill nozzle of an underground fuel storage tank to measure the tank wall thickness. The invention, in a preferred embodiment, uses ultrasonic thickness measurement technology, a well known inspection technique. A special type of ultrasonic probe known as a ZIP (Zero Interface Probe) is required to measure the thickness of fiberglass. A thickness measurement is accomplished by pressing the tool transducers firmly against the inside surface of the fiberglass tank after applying a couplant gel to the surface of the transducers. The tool is connected to an ultrasonic flaw detector, which generates a transmitted pulse and displays the transmitted and reflected pulses on a display screen. The thickness is determined by measuring the time-of-flight (on the display screen) between appropriate pulses.