Keep the turbine spinning – and keep producing. That’s the theory and generally it’s also the practice. But when the turbine stops, output stops, and getting the turbine running again becomes a critical priority.
Turbines are typically so reliable they almost get taken for granted. They are a vital power source, but they do stop. It could be one of the control valves – such as fuel feed or lubrication oil – that fails and brings about the stoppage.
Although manufactured to strict tolerances and to perform in the challenging environment that is a turbine, valves do wear and fail over time. Failures can range from inconvenient – which could see the turbine down for just a few hours – to a catastrophic overspeed event where the turbine is destroyed and, in some cases, cause damage to adjacent infrastructure.
A study in the US found that one of the leading causes of major steam turbine failure is an overspeed event. Of these failures, 70 per cent resulted from valves failing to close. Failures of the main steam stop or throttle valve to close accounted for 50 per cent of these destructive events, while the failure of an extraction valve to close accounted for the remaining 20 per cent.
As part of the expanded turbine valve service program, CMA has partnered with Voith, acknowledged as a world leader in the design and manufacture of control systems and technology for the power generation market.
Access to Voith’s comprehensive suite of valves and actuators for steam, gas or oil-fired turbines is giving CMA an edge in valve repair, rebuilds and upgrades. One of the Voith components attracting a lot of attention is the oil-free electro-mechanical actuator. Offering a compact, cost-effective drive solution along with dynamic, precise and stable control, this actuator is ideal for retrofitting in virtually any turbine control system.
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