Vol.8 No.1GA20-AA116-NT76-77 |
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Academic Articles | |||||
Regular Paper | Vol.8 No.1 (2016) p.1 - p.12 | ||||
Measurement of Flow Accelerated Corrosion Rate at an Elbow Pipe and Combination Effect of an Upstream Orifice |
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Yoichi UTANOHARA1,*, Koichi KAMAHORI1, Akira NAKAMURA1, and Michio MURASE1 | |||||
1Institute of Nuclear Safety System, Inc., 64 Sata, Mihama-Cho, Mikata-Gun, Fukui 919-1205, Japan |
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Abstract | |||||
Flow accelerated corrosion (FAC) rates at an elbow pipe with the diameter of D = 50 mm were measured by using corrosion sensors made of carbon steel. In addition, FAC rates at the elbow with an upstream orifice were measured to investigate the enhancement of FAC due to pipe geometries. The diameter ratio of the orifice was 0.5. The water temperature was 150 °C, the mean cross-sectional velocity was 4.98 m/s, the dissolved oxygen concentration was under 0.2 μg/kg, and pH was nearly neutral (about 7.0) at room temperature. The FAC rate was smaller at the intrados of the elbow pipe than at other circumferential locations due to low flow velocity near the inner surface. The ratio of the maximum FAC rate at the elbow pipe to the FAC rate in the straight pipe was about 3.7 without the upstream orifice and about 15.4 with the upstream orifice. This showed that the orifice significantly affected the FAC rate at the elbow pipe because of the short distance of 2.65D between the orifice and the elbow pipe. | |||||
Keywords | |||||
flow accelerated corrosion, elbow pipe, wall thinning rate, electric resistance method, orifice | |||||
Full Paper: PDF
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