Browsing by Author "Moss, CJ"

Now showing 1 - 5 of 5
  • No Thumbnail Available
    Item
    Development of the new Australian girth weld defect acceptance standards
    (Welding Technology Institute of Australia, 1994) Bowie, G; Barbaro, F; Moss, CJ; Fletcher, L
    The Australian pipeline code, in common with other areas of welded fabrication, has undertaken development of girth weld defect acceptance standards based on structural significance of the imperfection in addition to the traditional workmanship standards. The "fitness for purpose" approach adopted for the Australian pipeline code is related to that originating from the European pipeline Research Group (EPRF) which has compiled an extensive database of failure conditions of both real and artificial defects. The present paper reviews the relationship of EPRG guidelines and Standards Australia ME38 Committee, Welding Working Group draft revisions to Australian Standard AS2885,1987 hearinafter referred to as the draft AS2885.2. Attention is also drawn to the mechanical property requirements necessary to ensure girth weld integrity as well as the proposed research sponsored by the Cooperative Research Centre (CRC) to extend the pipe wall thickness range for the Australian pipeline industry.
  • No Thumbnail Available
    Item
    Evolution of an expert system for the engineering critical assessment of pipeline girth welds
    (Welding Technology Institute of Australia, 1994) Moss, CJ; Fletcher, L; Barbaro, F; Bowie, G
    AS2885 considers pipeline girth weld defect acceptance using and Tier Tier 1 (workmanship standards) 2 (fitness for purpose) and by Engineering Critical Assessment (ECA) as Tier 3. However, ECA is currently an unwieldy tool and unattractive to those who have only an occasional need to carry out assessment using fracture mechanics. A road map is described for the development of an ECA defect acceptance methodology. Input parameters to an ECA are also reviewed. The early stages in the evolution of an expert system, which aims to make the ECA route more accessible to the pipeline industry, are described.
  • No Thumbnail Available
    Item
    Life assessment and extension of HIFAR
    (The Institution of Engineers Australia, 1994-05-01) Jostsons, A; McDonald, NR; Moss, CJ
    HIFAR has now operated safely for more than 30 years, well beyond the original design expectations, with excellent availability for research and production of radioisotopes. The main reason for the longevity of HIFAR is the degree of conservatism of the design in the 1950's. The key components that affect the estimate of the useful life of HIFAR are presented. They include: the reactor aluminium tank (RAT), the graphite reflector and the reactor steel tank (RST) and shield cooling coils. An assessment of these components indicates that there are no foreseeable technical limitations to the operating life for the continued operation of HIFAR to 2025 at 10MW, in full compliance with safety requirements, provided that attention is paid to operating regimes, regular maintenance and replacement of other components. The costs of refurbishment of HIFAR and its facilities to the year 2025 are considerable. The paper concludes that the main risk from life extension is economic.
  • No Thumbnail Available
    Item
    Pipesafe, engineering critical assessment software for pipe line girth welds
    (New Zealand Welding Committee, 1996-02-04) Moss, CJ; Irrgang, R; Stathers, PA; Barbaro, F; Bowie, G
    The Australian Standard for Pipeline Construction, AS2885 (1995), considers pipeline girth weld defect acceptance using Tier 1 (workmanship standards), Tier 2 (fitness for purpose) and by Engineering Critical Assessment (ECA) as Tier 3. AS2885 makes provision for ECA in clause 22.4 by stating "if approved the acceptable criteria may be determined by using an approved ECA procedure or other approved method". The ‘fitness for purpose‘ approach adopted in AS2885 is related to that originating from the European Pipeline Research Group (EPRG). However, ECA is currently an unwieldy tool and unattractive to those who have only an occasional need to carry out assessment using fracture mechanics. This paper discusses the software PIPESAFE that has been developed to apply ECA defect acceptance methodology to girth welds in pipelines being built in Australia. PIPESAFE is a PC based software package which aims to enable pipeline engineers to assess the significance of flaws and is based on principles embodied in PD6493, 1991 ‘Guidance on Methods for Assessing the Acceptibility of Flaws in Fusion Welded Structures”. The software is currently being trialed in industry and will be commercially available in the near future.
  • No Thumbnail Available
    Item
    Weld repair of creep damaged steels
    (Welding Technology Institute of Australia, 1994) Croker, ABL; Harrison, RP; Moss, CJ
    A Cooperative Research Centre project "Welding of Thermally modified Structures" was commenced in June 1993 with support from ANSTO, CSIRO, BHP, University of Wollongong and the CRC for Materials, Welding and Joining. The main aims of the project are to quantify the effects of performing repair welds on materials which have operated for extended periods at elevated temperature. Welding is an increasingly used method for performing repairs, replacements, retrofits and modications to elevated temperature plant, however, the effects of these repairs on the ultimate life of a component are poorly understood. This paper presents details of the three ex-service materials chosen for the project, a carbon steel and two low alloy steels. Assessments have been made of their ex-service condition and a series of repair welds manufactured in preparation for a comprehensive testing and assessment program over the next 2 years. Work is also presented on development of new methods of assessing materials and components both destructively and non-destructively, along with new methods of modelling welded components in high temperature service.