The stresses in pipe flange connections with asbestos gaskets and non-asbestos gaskets subjected to internal pressure at room temperature are analyzed taking account of a hysteresis in the stress-strain curve of the gasket using axisymmetric theory of elasticity and a three-dimensional finite-element method (FEM) . The contact gasket stress distributions, the hub stresses and the variations in axial bolt force are examined in each pipe flange connection with asbestos and non-asbestos gaskets. The characteristics of the connections are demonstrated between asbestos and non-asbestos gaskets. Moreover, the amount of leakage is estimated using the basic gasket property obtained from JIS B 2490 and the contact gasket stresses obtained from the axisymmetric theory of elasticity and FEM. The estimated results are in a fairly good agreement with the experimental results obtained from the leakage tests, where spiral wound gaskets (SWG) are used. It is found that the differences in the contact gasket stress distributions between pipe flange connections with asbestos and non-asbestos gaskets are small. The sealing performance of the pipe flange connections with non-asbestos gasket is better than that with asbestos gasket at room temperature.

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This paper presents FRP cylinder for storing high pressure hydrogen gas with Cr-Mo steel liner and Carbon Fiber FRP. Specifically, it relates to an FRP cylinder using a thin Cr-Mo steel liner of thickness 3. 2mm which shows light-weightness same as Al liner FRP. This steel named 34CrMo44 is modified 34CrMo4: No. 17220, specified in EN-10083-3 (2006) and it contains 0. 3 to 0. 6% Mo and not contains intentionally adding Ni.
The 34CrMo44 steel shows good resistance to hydrogen embrittlement, especially excellent fatigue crack growth characteristic under high pressure hydrogen gas conditions. Thereby, 34CrMo44 liner FRP has suitability for a high pressure hydrogen accumulator cylinder in station or on-board tank for fuel cell vehicle.

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A guideline of fitness-for-service assessment to fire damage is introduced to API 579-1⁄ASME FFS-1 Code. Since the fire damage evaluation is based on the material degradation associated with heat exposure, the identification of heat exposure zone will be essential. The Code provides guidance to judge the heat exposure zone and one of useful information is temper colors of steels being different to the exposed temperature. But the reference temper colors are shown only by the designated colors without photographic examples in the Code. And also, further investigations may be carried out to test such mechanical properties as tensile strength, hardness, impact energy, ductility and so on for the damaged material. Interpretation of those test results should be endorsed by metallurgical analysis. However, the details of metallurgical analysis are not available in the Code. It is desirable for these points to be improved for more user friendliness. The Japanese Fitness-For-Service Committee organized by the Petroleum Association of Japan and the Japan Petrochemical Industry Association is working on the localization of fitness-for-service standard harmonizing with API⁄ASME. The Committee has prepared supplemental references for the photographic temper color examples and the guideline of metallurgical analysis, and proposes incorporating them into the Code. This paper presents the contents of those references prepared by the Committee. The temper color reference shows several photographic examples of different exposed temperature, elapsed time and cooling rates for carbon steel and stainless steel. The metallurgical analysis guide describes typical degradations in mechanical properties and appearances in microstructure observed in the materials exposed to fire, evaluation criteria, procedure for replica preparation, personnel qualification and so on.

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