Concentricity issue of the turbine control valve spool
Thread Content
Have you encountered situations where poor concentricity of the valve spool in a steam turbine control valve led to the breakage of the valve stem or deformation of the valve spool? How important is the calibration of this cylinder, joint bearing, and related supports? Recently, I encountered this situation again: not only was the stem of the control valve broken, but the valve core had also suffered severe deformation due to repeated contact with the packing, resulting in multiple grooves on its surface. What are the requirements for this concentricity during the actual maintenance and installation? Are there any relevant standards or specifications? Let’s discuss it together.
Reply to 1# julius6054: May I ask how the original poster is managing the steam leakage at the steam valve stem?
It’s already broken; what more can leak? The spring presses against the valve core, keeping the valve closed. Usually, there isn’t much leakage at the valve stem either; after all, since it’s able to hold the valve core in place in that manner, with all those layers of packing, the sealing effect is quite good.
Could it also be that the filler is pressed too tightly or deformed?