Liquid penetrant testing

Development of Theory and Practice of Liquid Penetrant Testing. 

General hydrodynamic theory for liquid penetrant testing (PT) has been worked out in [1], Basic principles of the theory were described in details in [2,3], This theory enables, for example, to calculate the minimum crack s width that can be detected by prescribed product family (penetrant, excess penetrant remover and developer), when dry powder is used as the developer. One needs for that such characteristics as surface tension of penetrant a and some characteristics of developer s layer, thickness h, effective radius of pores and porosity TI. One more characteristic is the residual depth of defect s filling with penetrant before the application of a developer. The methods for experimental determination of these characteristics were worked out in [4]. 

But there are two physical phenomena that were not taken into account in the frame of the theory [1-3], although our last researches demonstrate its principal significance for liquid penetrant testing. The aim of this study is to investigate these phenomena and to determine the restrictions on theory applicability. 

Another phenomenon is so called two-side filling of one-side closed conical capillaries with liquid [5]. On the one hand the more penetrant is trapped by the defect the wider indication will appear. Contrariwise it is almost impossible to extract a penetrant from the completely filled surface defects by dry developer [6]. In this study we propose the theory of the phenomenon. Besides experimental results of the investigation of two-side filling with various penetrants of conical capillaries are presented. Practical recommendations to optimize liquid penetrant testing process are proposed. 

Prokhorenko P.P., Migoun N.P. Introduction To Liquid Penetrant Testing Theory,... 

Liquid oxygen, 17 754 shipment of, 17 755 Liquid packaging board, 18 130-131 Liquid penetrant testing (PT), in... 

General corrosion control, prevention, and monitoring should be planned for from the onset. To detect and monitor corrosion, various methods must be used, while corrosion protection would be done by the addition of inhibition and use of protection coatings [5]. Visual examination, laser methods, the replication microscopy liquid penetration testing method, magnetic particles testing, the eddy current inspection method, acoustic emission technique, thermal methods of inspection, and nondestructive methods are the various methods to be adopted when monitoring pipeline corrosion [5]. 

Typical manufacturing sequence of an RPV component (shell). UT, ultrasonic test DT, dimensional test MT, magnetic particle test VT, visual test PT, liquid penetration test NDE, non-destructive examination PWHT, post-weld heat treatment. 

All full-penetration, pressure-containing welds are 100% radiographed to the standards of Section III of the ASME Boiler and Pressure Vessel Code. Weld preparation areas, back-chip areas, and final weld surfaces are magnetic-particle or dye-penetrant examined. Other pressure-containing welds, such as used for the attachments of nonferrous nickel-chromium-iron mechanism housings, vents, and instrument housings to the reactor vessel and head, are inspected by liquid-penetrant tests of the root pass, the lesser of one-half of the thickness or each 1/2-inch of weld deposit, and the final surface. Additionally, the base metal weld preparation area is magnetic-particle examined prior to overlay with nickel-chromium-iron weld metal. 

N. Tracy and P. O. Moore, eds.. Nondestructive Testing Handbook, Vol. 2 Liquid Penetrant Testing, 3rd ed., American Society for Nondestructive Testing, Columbus, Ohio, 1999. 

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