Nondestructive method for detection of defects and the condition of liners in polymer-lined pipes and equipment

摘要

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. Equipment containing defective liners may be removed from service before the defect causes a leak.