The deck plates of a single-deck-type floating roof for large oil storage tanks are joined by single-welded full-fillet lap joints. In areas with frequent strong winds, fatigue cracks sometimes occur in the welds of the deck plates. The aim of the present study is to investigate the effect of the gap imperfection of the lap joint on the fatigue life. Generally, weld imperfections significantly reduce the fatigue crack propagation life of the welded joints. A stress analysis using the finite element method was performed to provide the basic data for the fatigue crack growth analysis.

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The characteristics of hollow cylindrical bolted joints with plain washers under external tensile loadings are analyzed using elasto-plastic FEM such as the contact stress distributions, plastic displacement (permanent set) at the bearing surfaces and the load factor. The difference in the contact stress distributions between the joints with the washer and without the washer is demonstrated. The effect of thickness of the plain washers on the contact stress distributions and the plastic displacements are clarified. It is found that the effect of the plain washer specified in JIS B 1256 is small on the contact stress distributions and the plastic displacements. Also, the effect of the external load on the changes in the contact stress distributions and the plastic displacements at the bearing surfaces using the values of load factor is observed to be small. It is also found that as the thickness and Young's modulus of the plain washer increases, the plastic displacement decreases. It can be concluded that the elasto-plastic FEM stress analysis is useful for analyzing bolted joints tightened with higher bolt preloads.

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China is currently the most energetic country in the construction of aboveground oil storage tanks in the world. Numerous large-sized tanks are under construction at the oil stockpiling bases in China. This paper presents the situation of oil stockpiling strategy and the codes and standards of design, construction, maintenance and inspection for oil storage tanks in China.

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In 1994, a new piping seismic rule of ASME Section III which allowable stress level was rationalized based on the static and dynamic piping test results. Since then, ASME and NRC have had many meetings and discussions toward endorsement. During this period additional analyses and evaluations have been carried out to resolve NRC's concerns and the rule has been improved. The last and most important technical issue has been dynamic strain aging in carbon steel piping. Recently, NRC has acknowledged that dynamic strain aging at the strain rate during earthquake and at the service temperature is negligible and ASME rule is acceptable.
It is very important to know the background, technical basis and meaning of the rule to apply the ASME seismic piping rule to the actual nuclear piping and to improve the rule in future. It is a good time to summarize the rule-making process and current status of the rule, because the authors have always played a main role in this revision activity as ASME committee members.

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