Flow accelerated corrosion (FAC) is an unavoidable problem in the integral part of the pipe line systems of Nuclear Power Plants worldwide. This has a significant influence on the thickness loss of the pipe line which affects the operation and maintenance of the plants. During the prolonged operation of the plants, FAC leads to inside wall thinning, rupture and catastrophic failure of the pipeline systems and ultimate shutdown of the reactor system for maintenance. Qualitative coupon based chemical off-line analysis techniques were only followed earlier for the prevention of untoward incidents. With the introduction of ultrasonic nondestructive thickness measurements viz., pre-service, in-service and inspection during shutdowns, the possibility of accidents have been reduced to a maximum extent. However, detailed understanding of FAC and wall thinning of pipes due to different plant operation conditions such as flow velocity, different pH, different temperature and pressure values etc., are not available even today. The present experimental study is aimed to throw light on the parameters that have more impact on FAC. Also it is aimed to identify the vulnerable locations and wall thickness loss along the clock positions. The output of this study will gain currency while dealing with FAC code, and plays a critical role in the establishment of safe and reliable and continuous plant operations. According to existing literature, one of the most important parameters that affect FAC is the piping configuration i.e., geometry of flow path. Hence, the present study is aimed towards the understanding of FAC with respect to the bend angle and bend radius of the carbon steel piping. In this study, carbon steel pipes as per ASTM A106 Gr‘B‘ material with two bend angles viz. 58° and 73° with bend radius 2D and 4D, where D denotes the outer diameter of the pipe, have been chosen. These parameter ranges are available in the existing reactor and hence four different pipe bend specimens have been undertaken. Therefore, the four different pipe specimen holders of ASTM A106 Gr ‘B‘ materials having 15NB (Nominal Bore) pipe bends were designed and fabricated. Under the similar experimental conditions, using the Computational Fluid Dynamics (CFD) studies, the velocity distribution, the wall shear stress and the turbulent kinetic energy were simulated and correlated with the corresponding measured wear rate. Basic parameters like pipe material, bend angle, bend radius, etc. have been used for the simulation studies. Comparison of the simulated flow rate with the experimental values of wall thickness obtained through the ultrasonic measurements indicate that the bend angle and bend radius of the geometry play a crucial role on FAC.

流动加速腐蚀（FAC）是世界范围内核电站管道系统不可或缺的问题。这对管道的厚度损失有重大影响，这会影响设备的运行和维护。在工厂长时间运行期间，FAC会导致内壁变薄，管道系统破裂和灾难性故障，并最终关闭反应堆系统进行​​维护。基于定性优惠券的化学离线分析技术仅在较早时才用于防止不良事件。随着超声波无损厚度测量的引入，即停机前的服务，在役和检查，事故的可能性已得到最大程度的降低。然而，由于工厂运行条件不同（例如流速，不同的pH，不同的温度和压力值等），对FAC和管道壁变薄的详细了解直到今天仍无法获得。当前的实验研究旨在阐明对FAC有更大影响的参数。它还旨在确定时钟位置上的易损位置和壁厚损失。这项研究的成果将在处理FAC规则时获得成功，并在建立安全，可靠和连续的工厂运营中发挥关键作用。根据现有文献，影响FAC的最重要参数之一是管道配置，即流路的几何形状。因此，本研究旨在了解关于碳钢管道弯曲角度和弯曲半径的FAC。在这项研究中，碳钢管符合ASTM A106 Gr'B'材料，具有两个弯曲角度。选择了弯曲半径为2D和4D的58°和73°，其中D表示管道的外径。这些参数范围在现有反应器中可用，因此已进行了四个不同的弯管样品。因此，设计并制造了具有15NB（标称孔）弯头的ASTM A106 Gr'B'材料的四种不同的管样品支架。在相似的实验条件下，使用计算流体动力学（CFD）研究，速度分布 模拟壁面剪应力和湍流动能，并将其与相应的实测磨损率相关。基本参数（例如管道材料，弯曲角度，弯曲半径等）已用于模拟研究。将模拟流速与通过超声测量获得的壁厚实验值进行比较表明，几何形状的弯曲角度和弯曲半径对FAC起着至关重要的作用。