Steam Turbine Risk
Steam turbines are highly stressed rotating machines in which blade failures, bearing damage or water induction can cause total losses with long replacement lead times, making vibration monitoring and protective automation key loss prevention measures.
Failure mechanisms
Steam turbines operate at high speeds, temperatures and pressures and are correspondingly sensitive to deviations from design conditions. Water induction from wet or insufficiently separated steam can destroy blades within seconds, while bearing damage from misalignment, lubrication failure or foreign objects develops gradually and announces itself through rising vibration. Overspeed following a load rejection without a functioning trip system is among the most consequential failure scenarios.
Protection concept
Key protective elements are continuous vibration and bearing temperature monitoring, a reliable overspeed and trip system, and careful steam conditioning to prevent moisture and solids ingress. Recurring inspections of blading, bearings and seals during planned outages allow incipient damage to be detected before it reaches a critical state.
Insurance relevance
A total loss of a large steam turbine regularly causes a business interruption lasting several months, as replacement rotors or repair capacity are only available to a limited extent on the market. For machinery and business interruption insurance, vibration monitoring, inspection history and a documented spare parts strategy are therefore key criteria in risk assessment.
Standards and codes
- ISO 20816-2:2017 – Mechanical Vibration, Measurement and Evaluation of Machine Vibration, Part 2: Land-Based Gas Turbines, Steam Turbines and Generators in Excess of 40 MW