抄録
Fiber Reinforced Plastics (FRPs) are used as pipe, tank and duct in chemical plant because they have corrosion resistance and strength. However, FRPs might degrade slowly over a few decades. Since FRP and the other organic materials have been used rather recently and there is not so much information of durability compared with metals. Furthermore, applicable non-destructive test (NDT) on FRP is not confirmed yet. Hence, it is important to apply a NDT method on FRP equipment used in chemical plant. In this report, Ultrasonic Test (UT) inspected the degraded FRP tank used in chemical plant and error of UT was evaluated as standard deviation. The results of SEM, EDS and FT-IR indicated that degradation of this tank was categorized as 'surface reaction type'. Moreover, 'Damage Factor' in case of FRP tanks was calculated by reference to API 581 and 'Inspection Effectiveness' of UT was proposed from Risk Based Inspection points of view.