Leak-before-break and plastic collapse strength evaluation of stainless steel piping with a part-through notch

The present study examines the effects of the number of cracks and the crack interval on the plastic collapse strength of austenitic stainless steel (SUS304) piping with multiple cracks subjected to combined axial tension and bending. The goal of the present study is to simplify the structural integrity assessment of the stainless steel piping. Notches were cut in circumferential direction of the SUS304 pipes. The notch interval was 5 to 32 mm in the double-notched specimens. In the triple-notched specimens, the notches of the specimen were equally spaced. The notches at both ends of the triple-notched specimens were cut at the same interval as the double-notched specimens. The notched specimens were subjected to combined axial tension and bending. The plastic collapse strength of the notched specimens was dependent on the load history, and the plastic collapse strengths of the double- or triple-notched specimens was approximately equal to that of the single-notched specimens. These strengths were higher than the theoretical plastic collapse strength of the single-notched specimen based on an elastic-perfectly plastic material. Therefore, double or triple circumferential notches arranged in intervals of from 5 to 32 mm in SUS304 piping can be considered to be a single circumferential crack by applying the plastic collapse theory for an elastic-perfectly plastic material.

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Defect characterization in pipe-to-pipe welds in large-diameter stainless-steel piping

Materials Characterization ◽

10.1016/1044-5803(94)90078-7 ◽

1994 ◽

Vol 33 (2) ◽

pp. 155-162 ◽

Cited By ~ 1

Author(s):

D.E. Rawl ◽

S.L. West ◽

D.A. Wheeler ◽

M.R. Louthan

Keyword(s):

Stainless Steel ◽

Large Diameter ◽

Defect Characterization ◽

Steel Piping

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Inspection and mitigation for pitting corrosion on stainless steel process piping to prevent process safety event and loss production opportunity in Medco E&P

10.29118/ipa21-o-43 ◽

2021 ◽

Author(s):

I. Rosyadi

Keyword(s):

Stainless Steel ◽

Pitting Corrosion ◽

Sun Exposure ◽

Passive Layer ◽

Process Safety ◽

Pipe Surface ◽

Corrosion Propagation ◽

Process Piping ◽

Safety Event ◽

Steel Piping

Stainless steel piping has excellent corrosion resistant properties, both internal or external piping surface. In humid circumstances, sea vapor containing chlorine will be trapped on the pipe surface, especially pipes below deck with minimum sun exposure (more humid). Chlorine on the external pipe surface will damage the passive layer of stainless steel pipe. Damage speed is faster than recovery of passive layer stainless steel. This condition lead to a lot of localized pitting corrosion spread. The corrosion was detected visually and carried out with dye penetrant inspection to assure pitting condition. Actual dimension of pitting (depth, diameter) cannot be measured due to limitation of the NDE technique. This pitting corrosion can result hydrocarbon leakage as a process safety event that contributes loss of production opportunity. Without modification circumstances, this condition can be stopped immediately by application of a viscos elastic coating to prevent pitting corrosion propagation. Application of viscos elastic coating is simpler and faster when compared to conventional coating. Viscos elastic coating will protect stainless steel piping surface against oxygen and chloride in humid circumstances so that stainless steel can recover passive layer and stop pitting corrosion.

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Rupture Hardware Minimization in Pressurized Water Reactor Piping

Journal of Pressure Vessel Technology ◽

10.1115/1.3265641 ◽

1989 ◽

Vol 111 (1) ◽

pp. 64-71 ◽

Cited By ~ 1

Author(s):

S. K. Mukherjee ◽

J. J. Szy Slow Ski ◽

V. Chexal ◽

D. M. Norris ◽

N. A. Goldstein ◽

...

Keyword(s):

Stainless Steel ◽

Ferritic Steel ◽

High Energy ◽

Pressurized Water Reactor ◽

Pipe Failure ◽

Pressurized Water ◽

Screening Criteria ◽

Water Reactor ◽

Leak Before Break ◽

Generic Sense

For much of the high-energy piping in light water reactor systems, fracture mechanics calculations can be used to assure pipe failure resistance, thus allowing the elimination of excessive rupture restraint hardware both inside and outside containment. These calculations use the concept of leak-before-break (LBB) and include part-through-wall flaw fatigue crack propagation, through-wall flaw detectable leakage, and through-wall flaw stability analyses. Performing these analyses not only reduces initial construction, future maintenance, and radiation exposure costs, but also improves the overall safety and integrity of the plant since much more is known about the piping and its capabilities than would be the case had the analyses not been performed. This paper presents the LBB methodology applied at Beaver Valley Power Station—Unit 2 (BVPS-2); the application for two specific lines, one inside containment (stainless steel) and the other outside containment (ferritic steel), is shown in a generic sense using a simple parametric matrix. The overall results for BVPS-2 indicate that pipe rupture hardware is not necessary for stainless steel lines inside containment greater than or equal to 6-in. (152-mm) nominal pipe size that have passed a screening criteria designed to eliminate potential problem systems (such as the feedwater system). Similarly, some ferritic steel line as small as 3-in. (76-mm) diameter (outside containment) can qualify for pipe rupture hardware elimination.

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