We have a GE6541 Gas Turbine running on Natural gas.

Recently we observed that <b>Main Gas Pipe</b>, which surrounds the compressor casing like a ring and from which gas enters in different combustion chamber through different pipes, <b>vibrates continually in a large scale</b> while other closest pipe lines and turbine body remains fixed apparently.

Can anyone tell me why this <b>continual vibration</b> occurs and how we can minimize that?

 

Are you sure that the piping is properly supported? If the piping wasn't re-installed properly and has some kind of stress or strain on it, then it can pick up vibrations from the turbine and seem to accentuate them.

Most of the piping systems I have seen have some kind of "sliding" support, because of the temperature differentials. The natural gas piping is usually much cooler than the ambient temperature in the turbine compartment. So, the typical design for the piping tries to take the different expansion rates into consideration to reduce the mechanical stress on the piping.

You need to check and verify that the piping is properly installed and supported. Check the Piping Arrangement drawings provided in the Service Manual for details of how the piping was originally supported.

But this isn't likely a controls-related issue.