Liquid penetrant inspection

Magnetic Particle inspection Liquid Penetrant Inspection... 

Visual and other inspections (liquid penetration inspection in some case) are performed to pump casings during annual inspections. No cracks are found on the cast stainless steel casing of pumps and valves. 

Due to the well known human shortcomings the probability of finding flaws using Magnetic Particle Inspection (MPI) or Liquid Penetrant Inspection (LPI) can be restricted to only 60-85% and the inspection reproducablity is difficult. 

With the objective determination of the visibilitity of magnetic particle indications quantitative researches on the influence of the inspection parameters will be possible. The first part deals with the type testing of detection media which is as well on the course of adoption for type testing of liquid penetrant systems (prEN 751-2). 

R. C. McMaster, ed., "Liquid Penetrant Inspection," Nondestructive Testing Handbook, Vol. 2, 2nd ed., American Society for Nondestmctive Testing, Columbus, Ohio, and the American Society for Metals, Cleveland, Ohio, 1982. 

Practice for Liquid Penetrant Inspection Method Practice for Magnetic Particle Examination Quality Standard for Steel Castings and Forgings for Valves, Flanges and Fittings and Other Piping Components — Magnetic Particle Examination Method... 

Plate edges shall be inspected by magnetic particle or liquid penetrant examination as required by Section VIII, Division 1, UG-93(d)(3), of the ASME Code. 

A552 Liquid penetrant inspection of connection welds NOZZ LP c 1 1 lyes (true) Oi no (telse)... 

Liquid Penetrant Inspection Useful to find surface discontinuities. Can be used with any material that has a reasonably smooth nonporous surface. 

Magnetic Particle Inspection Useful to find surface discontinuities and some discontinuities very near the surface in ferromagnetic materials. More sensitive than liquid penetrant inspection. 

NDE shall be performed as required by the material specification. If additional radiographic, ultrasonic, magnetic particle or liquid penetrant examinations of the welds or materials are specified by the purchaser, the methods and acceptance criteria shall be in accordance with the standards shown in Table 13. Alternative standards may be proposed by the vendor or specified by the purchaser. The welding and material inspection data sheet in Annex N may be used for this purpose. 

Liquid penetrant inspection Section V, Articles 6 and 24 of the AS ME Code Section VIII, Division 1, Appendix 8 of the ASME Code Section VIII, Division 1, Appendix 7, of the ASME Code... 

Nondestructive evaluation, also termed nondestructive testing or nondestructive inspection, is extensively used in weld testing (14). Nondestructive tests do no impair the serviceability of the material or component under stress. The most widely used tests for evaluation of welds are liquid penetrant, magnetic particle, ultrasonics, and radiography. Acoustic-emission tests are increasingly used. Nondestructive tests detect and characterize, in terms of size, shape, and location, the various types of weld discontinuities that can occur. 

Failure Investigation. The clamp was nonmagnetic and the stamped identification on the side of the U-shaped shells indicated that they were fabricated from forged 304 austenitic stainless steel. Visual examination of the fracture surfaces revealed they were entirely brittle and exhibited a very coarse fracture morphology. Liquid penetrant inspection revealed the presence of additional cracks in the fractured half of the clamp. There was no cracking present in the high-strength steel fasteners. 

LIQUID PENETRANT INSPECTION - A type of nondestructive inspection that locates discontinuities that are open to the surface of a metal by first allowing a penetrating dye or fluorescent liquid to infiltrate the discontinuity, removing the excess penetrant, and then applying a developing agent that causes the penetrant to seep back out of the discontinuity and register as an indication. 

A penetrant dye is sprayed onto the surface of the composite inspected. The liquid infiltrates cavities and is made visible by applying a developer to the surface. Defect size is indicated by the color intensity and the rapidity of infiltration of the liquid penetrant. Two types of penetrant, visible and fluorescent, can be used. Fluorescent dyes are visible under UV light, while the visual dyes are visible under normal light. The choice of the penetrant is function of the material tested and the sensitivity required. Automatic dye penetrant inspection systems exist that transfer and apply the dye, apply the revealing agent (or developer), and finally clean the part after testing. How ever. only specific shapes can be inspected automatically, and manual inspection is still required for most structures. 

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]. 

In February 1998, while readjusting the setting of SG safety valves in cold state, water leak was observed in one of the bosses in experimental thermo well in the steam sub header of one of the SG modules. The leaking boss and plug were replaced with dummy piece and all other similar welds were checked for any defects by liquid penetrant inspection. Investigation revealed that failure is due to lack of heat treatment during fabrication. 

Methods for sealing the metal surfaces of the test devices against nonwoven fabrics should be explored because leaks may be confused with penetration and recorded as a test failure. Test methods which quantify the liquid penetration rather than detect it with visual inspection should be developed and compared with others. 

Examinations will include liquid penetrant or magnetic particle techniques when surface examination is specified, ultrasonic or radiographic techniques when volumetric examination is specified, and visual inspection techniques will be used to determine surface condition of components and for evidence of leakage. Specific techniques, procedures and equipment, including any special techniques or equipment will be in accordance with the requirements of IWA-22 00 of ASME Section XI and will be defined in the in-service inspection program. 

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. 

Liquid penetrant examination or magnetic particle methods and 100% volumetric examination by ultrasonic methods will be conducted at about ten-year intervals during the plant shutdown coinciding with the in-service inspection schedule as required by the ASME Code, Section XI. 

The reactor coolant pump pressure boundary is nondestructively inspected as required by ASME Section III for Class 1 components. The pump casing inspections include complete radiography and liquid penetrant or ultrasonic testing. The pump receives a hydrostatic pressure test in the vendor s shop and with the Reactor Coolant System. Inservice inspection of the pump pressure boundary will be performed during plant life in accordance with ASME Section XI. 

Liquid-Penetrant Inspection is a method of testing for surface defects or sub-surface defect with surface openings by relying upon a penetrant seeping into the defect. It is normally used for non-magnetic materials. 

Repair welds always must be carefully executed, and all traces of liquid-penetrant inspection material must be removed. Generally, inspection is performed on both faces of the repair weld and several inches beyond the repaired area. 

Visual Inspection Eddy current Radiography Acoustic emission Liquid penetrant Ultrasonic... 

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