B61 Mod 12 Life Extension Program Tailkit Assembly (B61 Mod 12 LEP TKA)

2015 ◽  
Author(s):  
John Mistretta
Keyword(s):  
Life Extension ◽  
Extension Program

Initial Implementation of IHI Zone Logic Technology at Philadelphia Naval Shipyard

1989 ◽  
Vol 5 (02) ◽  
pp. 79-89
Author(s):  
Koichi Baba ◽  
Takao Wada ◽  
Soichi Kondo ◽  
M. S. O'Hare ◽  
James C. Schaff
Keyword(s):  
Service Life ◽  
Life Extension ◽  
Initial Application ◽  
Initial Implementation ◽  
Late Fall ◽  
The Future ◽  
Service Life Extension ◽  
Extension Program ◽  
Technical Services

Philadelphia Naval Shipyard's application of zone logic to ship overhaul is neither small nor isolated. PNSY started its implementation of zone logic in the late fall of 1986, targeting the Service Life Extension Program (SLEP) for USS Kitty Hawk (CV-63) as the initial application. The technical services of Ishikawajima-Harima Heavy Industries Co., Ltd. (IHI), Japan were contracted to assist in this transition. This implementation on the Kitty Hawk is not a trial effort but involves about one third of the production man-days and covers over one half of the compartments on the ship. The actual SLEP production work on Kitty Hawk began in January 1988. Even though it is early in the three-year SLEP, zone logic already is proving its worth. This paper explains the zone logic methods and methodology applied at PNSY on Kitty Hawk. It also discusses the future of zone logic at PNSY and its continued application.

The Importance of High Energy Piping Support Maintenance to Enhance System Useful Life

2015 ◽  
Author(s):  
Samuel A. Huff ◽  
John P. Leach ◽  
Daniel S. Vail
Keyword(s):  
High Energy ◽  
Life Extension ◽  
Piping System ◽  
Support Design ◽  
Piping Systems ◽  
Proper Design ◽  
Useful Life ◽  
High Level ◽  
Extension Program

As part of the design basis of any piping system utilized to convey materials, pipe supports are required to ensure those pipes remain in their designed locations and do not overly expand or move due to sustained or occasional loads. These loads represent the total forces and moments in the piping components and as a result create stresses that affect the life of the component. Proper design and maintenance of these supports per the applicable codes and standards provide a reasonable life expectancy for the piping systems. This presentation will review the various codes and standards utilized for both pipe support design and maintenance. A high level overview of what information must be obtained to perform an analysis and meet ASME B31.1 Power Piping code requirements when modifying piping systems will be presented. Specific inputs to system design and computational software including material properties, stress intensification factors (SIF), thicknesses and tolerances, pressures, temperatures, insulation, coatings, the occasional loads, etc. will be discussed. Guidelines will be discussed for determining what piping modifications warrant a full pipe stress analysis to be performed. Recommendations for pipe support maintenance inspections will be provided to facilitate increased life expectancies of subject piping systems. The mandatory requirements of ASME B31.1 Chapter VII will be discussed, as well as recommendations from the non-mandatory appendix. Implementing maintenance programs at existing facilities will be discussed. Step by step recommendations for how to apply these guidelines within a long-term life extension program will be given. Tolerances and general guidelines associated with these programs will also be discussed. Finally, common pipe support failures, what they can affect, and how to look for early indicators of fatigue or failure will be covered.

Fatigue Damage Repair and Life Extension of a Floating Production Unit: The VFB Platform Revisited

2011 ◽  
Author(s):  
P. J. Haagensen ◽  
J. E. Larsen ◽  
O. T. Va˚rdal
Keyword(s):  
Fatigue Damage ◽  
Fatigue Cracks ◽  
Fatigue Cracking ◽  
Life Extension ◽  
Conference Paper ◽  
Safe Operation ◽  
Damage Repair ◽  
Production Platform ◽  
Low Levels ◽  
Extension Program

The Veslefrikk B platform was built in 1985 as a drilling exploration unit but was converted to a production platform in 1989. After only two years in service fatigue cracks were discovered and several repairs were made. However, extensive fatigue cracking continued and a retrofitting program was planned. In addition, increased payload was necessitated by more topside equipment required for a tie-in to the Huldra field which was scheduled to start production in 2001. In 1999 the platform was temporarily decommissioned and dry-docked for a comprehensive repair and upgrading program, this was completed in approximately two months. The life extension program was described in the OMAE 2000 conference paper 2954. However, after only one more year of service new cracks were found and subsequent fatigue damage necessitated new repairs. It is noteworthy that cracking this time occurred only in areas of the structure that were left untreated in the 1999 retrofitting program due to assumed low levels of stress in those areas. The paper describes the original repair and strengthening program, and the types of subsequent fatigue damage that required new repairs. Most of the cracks occurred in the hull skin plates and caused water leakage. The objective of the recent life extension program is to ensure safe operation of the platform for a period of another 20 years.

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