Hi all members !
I am young mechanical engineer. I have just worked in Power plant for 2 years so I have a little experience in this field. My plant have two Francis Turbines and two Turbine Inlet Butterfly Valves (TIBV). Nearly, my TIBVs are broken down and the main reason is the TIBV that cannot fall down (by counter weight) when it close. All TIBVs are the same error. I don't known why they are. It takes a lot of time for researching but I haven't discovered yet the best solution. So, I need helps from forum who can explain to me the way to repair may TIBV. Thanks a lot.