A Preliminary Study of Internal Corrosion in Condensate Pipelines at Geothermal Power Plants

Author(s):  
Ahmad Royani ◽  
◽  
Siska Prifiharni ◽  
Gadang Priyotomo ◽  
Joko Triwardono ◽  
...  

In this study, we presented observations and analyze related to internal corrosion in condensate pipes in geothermal power plants. A damaged pipe of condensate pipeline taken from a power plant was investigated to determine the root cause of failure. The observation and failure analysis was carried out by visual and dimensional examination, chemical composition testing, macroscopic, and microscopic examination, Scanning Electron Microscope (SEM) examination with Energy Dispersed Spectrometer (EDS). The deposit in the pipe was analyzed by X-Ray Diffraction (XRD). The quality of the condensate fluid and their tendencies were determined by Langelier Saturation Index (LSI). Also, the corrosion rate of the pipe was simulated by condensate fluid by using a corrosion measurement system (Tafel polarization). The internal corrosion was found in the condensate line is strongly suspected to occur due to erosion-corrosion. Erosion corrosion is caused by insoluble and hard particles in the condensate fluid. The results of XRD found the presence of calcium-silicate compounds in the sediment that is suspected to be the cause of erosion particles. The reduction of the thickness of the bottom pipe wall and occurs in longitudinal directions the alleged damage to the pipe due to sediment corrosion. The presence of hard compounds and differential oxygen can accelerate the process of corrosion so that the corrosion rate in condensate pipelines was a category in the severe category based on NACE SP0775 standards.

2018 ◽  
Vol 11 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Lin Xu ◽  
Jie Xu ◽  
Ming-biao Xu ◽  
Si-yang Li ◽  
Shuai Liu ◽  
...  

Introduction: The production casing of 3% Cr steel has encountered severe internal corrosion in Huizhou Oilfield. To disclose corrosion behavior of inner casing, a series of corrosion exposure tests were systematically conducted on 3% Cr coupons in terms of in-field conditions. Material and Methods: Influence of exposure time, temperature, and water-cut on the CO2 corrosion of 3% Cr steel was investigated, and analyses on weight loss, composition and morphology of corrosion product, and Tafel polarization curves were further carried out. Result: The results showed that the corrosion rate of 3% Cr steel increased with increasing temperature, but such trend descended when the temperature exceeded 65°C due to formation of an compact and adherent corrosion product film on the surface of 3% Cr coupons. While varying exposure time from 7 days to 14 days, the corrosion rate decreased, and the Cr and O enrichment was determined in the corrosion products. The corrosion rate of 3% Cr steel increased with a continuous increment of water-cuts, especially when the water-cut was larger than 40%. Conclusion: The localized corrosion can happen at the lower water-cut due to the presence of amorphous films. The main corrosion products were FeCO3, Cr5O12, Fe2O3, and Fe-Cr. Entry of CO2 to the simulated formation water caused an increase in the anodic Tafel slope, and accelerated dissolution of 3% Cr steel.


Alloy Digest ◽  
1993 ◽  
Vol 42 (11) ◽  

Abstract AL 29-4C is a highly corrosion resistant alloy with a relatively high strength. This combination allows the use of lighter gage tubes, and has led to its use in the brine heat exchangers of geothermal power plants. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming and joining. Filing Code: SS-554. Producer or source: Allegheny Ludlum Corporation.


2018 ◽  
Author(s):  
Liangshan Chen ◽  
Yuting Wei ◽  
Tanya Schaeffer ◽  
Chongkhiam Oh

Abstract The paper reports the investigation on the root cause of source-drain leakage in bulk FinFET devices. While the failing device was readily isolated by nanoprobing technique and the electrical analysis pinpointed the potential defect location inside the Fin channel, the identification of physical root cause went through extreme challenges imposed by the tiny-sized device and the unique FinFET 3D architecture. The initial TEM analysis was misled by the projection of a species in the lamella surface and thus could not explain the electrical data. Careful analysis on the device structure was able to identify the origin of the species and led to the discovery of the actual root cause. This paper will provide the analysis details leading to the findings, and highlight the role of electrical understanding in not only providing guidance for physical analysis but also revealing the true root cause of failure in FinFET devices.


Author(s):  
Clarence Rebello ◽  
Ted Kolasa ◽  
Parag Modi

Abstract During the search for the root cause of a board level failure, all aspects of the product must be revisited and investigated. These aspects encompass design, materials, and workmanship. In this discussion, the failure investigation involved an S-Band Power Amplifier assembly exhibiting abnormally low RF output power where initial troubleshooting did not provide a clear cause of failure. A detailed fault tree drove investigations that narrowed the focus to a few possible root causes. However, as the investigation progressed, multiple contributors were eventually discovered, some that were not initially considered.


Author(s):  
Michael Woo ◽  
Marcos Campos ◽  
Luigi Aranda

Abstract A component failure has the potential to significantly impact the cost, manufacturing schedule, and/or the perceived reliability of a system, especially if the root cause of the failure is not known. A failure analysis is often key to mitigating the effects of a componentlevel failure to a customer or a system; minimizing schedule slips, minimizing related accrued costs to the customer, and allowing for the completion of the system with confidence that the reliability of the product had not been compromised. This case study will show how a detailed and systemic failure analysis was able to determine the exact cause of failure of a multiplexer in a high-reliability system, which allowed the manufacturer to confidently proceed with production knowing that the failure was not a systemic issue, but rather that it was a random “one time” event.


2001 ◽  
Vol 1 (3) ◽  
pp. 91-96 ◽  
Author(s):  
L.J. Hem ◽  
E.A. Vik ◽  
A. Bjørnson-Langen

In 1995 the new Skullerud water treatment plant was put into operation. The new water treatment includes colour removal and corrosion control with an increase of pH, alkalinity and calcium concentration in addition to the old treatment, which included straining and chlorination only. Comparative measurements of internal corrosion were conducted before and after the installation of the new treatment plant. The effect of the new water treatment on the internal corrosion was approximately a 20% reduction in iron corrosion and a 70% reduction in copper corrosion. The heavy metals content in standing water was reduced by approximately 90%. A separate internal corrosion monitoring programme was conducted, studying the effects of other water qualities on the internal corrosion rate. Corrosion coupons were exposed to the different water qualities for nine months. The results showed that the best protection of iron was achieved with water supersaturated with calcium carbonate. Neither a high content of free carbon dioxide or the use of the corrosion inhibitor sodium silicate significantly reduced the iron corrosion rate compared to the present treated water quality. The copper corrosion rate was mainly related to the pH in the water.


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