We recently installed some and are still in the process of others.
I personally have not dealt with them but referred your question to a coworker who has. His responses are below.
On a strictly HP/IP upgrade only, we went from ~600 MW’s to ~640 MW’s on both units without increasing throttle pressure, or any other variables.
We had to go to single valve only operation on control valves. On a digital EH system this was no big deal, but could be on an older MHC system.
HP/IP turbine is far more sensitive to vibration induced rubs, although the machines are very well balanced and required no balancing after installation.
Radial and axial clearances are much tighter. Start-ups must follow differential temperature limits as a result.
It appears the efficient blading is more prone to carry over and foreign object damage and drop in efficiency. We are experiencing significant efficiency drops and are still trying to figure out what is causing the problems.
If you have any other questions, give me your e-mail and I will forward them on.
