Material characterization and evaluation of Fyrquel effect on the metal part of filters in a system EHC

In recent years, unexpected stoppages in power plants have been associated with problems in electro-hydraulic control systems (EHC) which generally operate with fluids to high pressure resistant to fire, but sensitive to the presence of water and contaminants that can promote damage and malfunction of government and discharge valves. The analysis here presented was performed to two filters prior to the servo valves of an EHC system that came out of service as a result of damage to these components. The study is based on analysis and inspection of metal and filter elements of these devices, integrating both chemical characterization by energy-dispersive X-ray spectroscopy of waste as materials that comprise both filters. The assessment made allowed documenting a poor design of the devices, same that promoted the stagnant fluid (Fyrquel), locally modifying the chemical composition of the medium, prompting the activation of auto-catalytic degradation processes that acidified the environment; the acid ph solutions began in susceptible sites of electrochemical corrosion processes which increased the Fyrquel contamination. (Author)