Condition Monitoring Systems

Casing Expansion Monitoring

Large turbines are often attached to their foundations by the footings surrounding the exhaust hood from one of the low pressure turbines; as the machine train warms up, all of the other components will grow outwards from that point; it is this expansion which is called Casing Expansion (CE).

During the start-up and run-down phases of any large machine, the turbine case (stator) and the enclosed rotating turbines (rotor) will tend to expand or contract at different rates, and therefore monitoring the CE is vital to ensure that serious turbine damage does not occur.

The location of the fixed or pin point on a particular machine will determine the requirements for casing expansion and will also dictate the type of transducers or sensors used; in practice, non-contact eddy current probes will usually be used for the rotor, and LVDTs will often be used for the stator or casing.

More about Casing Expansion (CE) – click here