scholarly journals Flow-Accelerated Corrosion in Pipe Wall Downstream of Orifice for Water and Air-Water Bubble Flows

2016 ◽  
Vol 04 (03) ◽  
pp. 93-103 ◽  
Author(s):  
Toshihiko Shakouchi ◽  
Koichi Kinoshita ◽  
Koichi Tsujimoto ◽  
Toshitake Ando
Keyword(s):  
Pipe Wall ◽  
Accelerated Corrosion ◽  
Flow Accelerated Corrosion

Effects of Flow Accelerated Corrosion on Piping Steady-State Vibration Evaluations

2003 ◽  
Author(s):  
Brian J. Voll
Keyword(s):  
Steady State ◽  
Nuclear Power ◽  
Power Plants ◽  
Pipe Wall ◽  
Vibration Monitoring ◽  
Accelerated Corrosion ◽  
Monitoring Programs ◽  
Wall Thinning ◽  
Piping Systems ◽  
Flow Accelerated Corrosion

Piping steady-state vibration monitoring programs were implemented during preoperational testing and initial plant startup at most nuclear power plants. Evaluations of piping steady-state vibrations are also performed as piping and component failures attributable to excessive vibration are detected or other potential vibration problems are detected during plant operation. Additionally, as a result of increased flow rates in some piping systems due to extended power uprate (EPU) programs at several plants, new piping steady-state vibration monitoring programs are in various stages of implementation. As plants have aged, pipe wall thinning resulting from flow accelerated corrosion (FAC) has become a recognized industry problem and programs have been established to detect, evaluate and monitor pipe wall thinning. Typically, the piping vibration monitoring and FAC programs have existed separately without interaction. Thus, the potential impact of wall thinning due to FAC on piping vibration evaluations may not be recognized. The potential effects of wall thinning due to FAC on piping vibration evaluations are reviewed. Piping susceptible to FAC and piping susceptible to significant steady-state vibrations, based on industry experience, are identified and compared. Possible methods for establishing links between the FAC and vibration monitoring programs and for accounting for the effects of FAC on both historical and future piping vibration evaluations are discussed.

C219 Velocity field characteristics at pipe-wall thinning position induced by Flow-Accelerated Corrosion

2010 ◽  
Vol 2010.15 (0) ◽  
pp. 367-368
Author(s):  
Masashi Tatematsu ◽  
Sheng Feng ◽  
Shingo Furuya ◽  
Masaya Kondou ◽  
Yoshiyuki Tsuji
Keyword(s):  
Velocity Field ◽  
Pipe Wall ◽  
Accelerated Corrosion ◽  
Wall Thinning ◽  
Flow Accelerated Corrosion

Proposal of the Estimation Equation of Flow Accelerated Corrosion Under Water-Steam Two-Phase Flow

2013 ◽  
Author(s):  
Masaaki Satake ◽  
Kimitoshi Yoneda ◽  
Ryo Morita ◽  
Fumio Inada
Keyword(s):  
Flow Condition ◽  
Two Phase Flow ◽  
Pipe Wall ◽  
Prediction Equation ◽  
Phase Flow ◽  
Two Phase ◽  
Accelerated Corrosion ◽  
Water Steam ◽  
Flow Accelerated Corrosion ◽  
Thinning Rate

Flow accelerated corrosion (FAC) is one of the pipe wall thinning phenomena. There are a few prediction equations for FAC under the two-phase flow condition, but their accuracy is uncertain. In this study, these equations are summarized. A new prediction equation is proposed, in which the liquid film velocity near the wall is taken into account. Also, FAC experiments with water-steam two-phase flow are performed. The thinning rate is predicted by calculation and compared with the experimental value.

Studies on Flow and Pipe Wall Thinning and the Reduction in the Downstream of Orifice Nozzle

2011 ◽  
Author(s):  
Toshihiko Shakouchi ◽  
Takayuki Suzuki ◽  
Hideki Yuya ◽  
Masaki Naruse ◽  
Koichi Tsujimoto ◽  
...  
Keyword(s):  
Cavitation Erosion ◽  
Pipe Wall ◽  
Liquid Droplet ◽  
Piping System ◽  
Droplet Impingement ◽  
Accelerated Corrosion ◽  
Wall Thinning ◽  
System 1 ◽  
Flow Accelerated Corrosion ◽  
Droplet Impingement Erosion

In a piping system of power plant, pipe wall thinning by Flow Accelerated Corrosion, FAC, Liquid Droplet Impingement Erosion, LDI, and Cavitation Erosion, C/E, are very serious problems because they give a damage and lead to the destructtion of the piping system[1]–[6]. In this study, the pipe wall thinning by FAC in the downstream of orifice nozzle, flow meter, is examined. Namely, the characteristics of FAC, generation mechanism, and prediction of the thinning and the reduction are made clear by experimental analysis. As a results, it was made clear that (1) the thinning is occurred mainly according to the size of the pressure fluctuation p′ on the pipe wall and the thinning can be estimated by it, and (2) the suppression of p′ can be realized by replacing the orifice to a taper shaped one having an angle to the upstream.

An Analytical Solution for Piping Non-Planar Flaws

2014 ◽  
Author(s):  
Phuong H. Hoang ◽  
Chee W. Mak
Keyword(s):  
Cross Section ◽  
Nuclear Power ◽  
Pipe Wall ◽  
Axial Loading ◽  
Limit Load ◽  
Element Analysis ◽  
Axial Section ◽  
Accelerated Corrosion ◽  
Pressure Limit ◽  
Flow Accelerated Corrosion

Recent studies on the effect of multi-axis loading on piping non-planar flaws indicate that the ASME Section XI, Appendix C pressure limit load approach for planar axial flaws can be used for evaluation of non-planar flaws provided that the effect of multi axial loading is to be considered. Finite element analysis results presented in this paper also indicate that bending limit load for planar circumferential flaws can be used for evaluation of non-planar flaws subjected multi axial loading. These studies used idealized uniformly thin rectangular flaws whose projected flaw geometry on pipe cross section and on pipe axial section are the same as the circumferential flaw geometry and the axial flaw geometry defined ASME B&PV, Section XI Appendix C. Sample problems with actual pipe wall thinning flaws due to flow accelerated corrosion and pitting in nuclear power plant are utilized for a comparison of the proposed methodology with various methodologies currently used by the industry for locally thinning pipe flaw evaluations.

Numerical Evaluation of Wall Thinning Profile in Separation and Union Pipe due to Flow Accelerated Corrosion

2014 ◽  
Author(s):  
Shun Watanabe ◽  
Kimitoshi Yoneda
Keyword(s):  
Wall Thickness ◽  
Power Plants ◽  
Pipe Wall ◽  
Branch Pipe ◽  
Residual Lifetime ◽  
Accelerated Corrosion ◽  
Geometry Factor ◽  
T Tube ◽  
Wall Thinning ◽  
Flow Accelerated Corrosion

Flow Accelerated Corrosion (FAC) is a pipe wall thinning phenomenon to be monitored and managed in power plants with high priority. In Japan, its management has been conducted with conservative evaluation of thinning rate and residual lifetime of the piping based on wall thickness measurements. However, noticeable case of the wall thinning occurred at separation and union pipe. In such pipe system, it is a problem to manage a section beneath reinforcing plate of T-tube pipe and a crotch of T-joint pipe; wall thickness measurement with high accuracy is difficult to conduct in the region by using ordinary ultrasonic testing devices. In this study, numerical analysis for separation and union parts of T-tube and T-joint pipes was conducted, and wall thinning profile by FAC was evaluated by calculating mass transfer coefficient and geometry factor. Based on these results, applicable wall thinning management for T-tube and T-joint pipes was considered. In the case of union flow from main and branch pipe, the wall thinning profile of T-tube showed the tendency of increase at main pipe like semielliptical region. On the other hand, noticeable profile appeared at crotch in T-joint although it was found that geometry factor of T-joint in this flow pattern was half the value of T-tube. An alternative evaluation method to previous one might be needed for such semielliptical region in T-tube and crotch in T-joint.

Sign in / Sign up

Export Citation Format

Share Document