EHC & MHC System Flushing
A Flushing Service that Lasts
One of the highest categories of forced outages on electrohydraulic controlled (EHC) steam turbines over the past 20 years has been the Turbine Trip and Monitoring System. This system consists of electrical relays, mechanical valves, and the high pressure fluid system. In a majority of cases, the fluid system was either directly or indirectly responsible for forced outages. Fluid contamination was found to be the single biggest recurring problem in the high pressure fluid system.
Since the fluid is the heart of the system, contamination has become a major concern in maintaining unit reliability. The only way to remove harmful fluid deposits is through a systematic flushing process that dissolves these deposits. The flushing fluid used contains acids that dissolve deposits and flush them back to the reservoir where they are removed. The acids are then removed from the hydraulic system following the flush.
The flushing procedure includes the following elements:
- An on-site meeting conducted prior to the flush to go over details including scheduling man-power, supplies, etc.
- A customized, flushing procedure based on years of experience
- A complete list of supplies needed for the flush including part numbers, quantities, and suppliers
- An external kidney loop filtering unit that assures no particulates are added to the system when adding fluid to the reservoir during the flush. This system considerably shortens the flush time.
- Experienced on-site system engineers to act as the technical directors for your supplied labor force to assure proper procedures are followed throughout the flush
- An on-site independent fluid analysis representative who will be taking fluid samples and analyzing the fluid throughout the flush
- A thorough after-action report detailing the initial state of the system, the steps performed, and the results