Leak in the turbine control steam valve
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I would like to ask if anyone has encountered steam leakage from the valve stem of a turbine control valve? How was it handled? What are the steps for replacing the packing? What if it’s necessary to replace the valve stem? I haven’t encountered it yet; thank you all for your advice.
We’ve changed it several times; it depends mainly on the leakage situation. Usually, if a leak is detected, tightening the packing nut promptly usually gives good results – we just tightened it again yesterday! If it cannot be tightened or the tightening doesn’t have an obvious effect, there is no choice but to wait until it stops working and then replace it! If the leakage is not severe or there isn’t enough time for emergency repairs, it’s not necessary to remove the valve stem when replacing it. All that’s needed is to take out the top spring and the thin plate that covers it, remove the compression nut, use a packing removal tool to remove some of the old packing, and then insert a few new packing rings. Make sure they are installed with proper alignment; sometimes it’s necessary to insert a few rings first, apply pressure, then add more rings. Do not apply too much pressure at first, otherwise the valve stem will not be able to move freely. If leakage occurs after installation, apply more pressure! If a major overhaul is required or if there is suspicion of defects caused by steam erosion on the valve stem, then that set of bolts must be removed as well; the small flange cover together with the valve stem must be taken out for inspection and replacement! When performing a complete replacement, some filler rings without openings can be installed; that’s more or less it
It is impossible to replace the packing without affecting production. In such cases, one can turn to a professional pressure-sealing company to drill a hole at the packing box and inject graphite packing – and voilà, the problem is solved!
I’ve learned it.* Replacing the packing definitely requires shutting down the machine. Looking at the position in the first picture, it doesn’t seem too tight; it will be necessary to find an opportunity to pull out the valve stem in order to check the packing. It’s not possible to simply replace the packing.
There is a leak in the control valve rod of the steam turbine; in less severe cases, the tightening nut can be adjusted, but in more serious cases, the machine must be shut down for replacement of the packing
How are the valve stem and the valve beam connected? Do I need to adjust anything after taking it apart and putting it back together? Thank you!
This was taken by the technician during maintenance; I hope it’s useful to you