How to repair a damaged actuator for large butterfly valves
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As shown in the figure, for the DN500 flanged butterfly valve, only the valve shaft remains. The actuator is connected to the sector gear shaft through a drive shaft; it gets damaged when trying to open the valve, and at present the valve is in a fully closed state. Since it is difficult to open the valve, tools such as pipe wrenches cannot be used to open it manually either. The medium inside the pipe is pressurized industrial water, and it is not possible to cut off the water supply; therefore, replacing the valve is not considered. I would really appreciate it if you could help come up with some ideas.
A square piece is placed at the top of the valve shaft; a sleeve is used to connect to the valve stem, and an extended lever is employed to open it.
Thank you for the reply. It might be possible to open it with a very long lever, but it would need to be returned to the manufacturer; using a lever every time isn’t feasible either
Add worm gears and worms; that should solve it
Replace with a new actuator; if it cannot be opened, the load must be removed before proceeding. Once the valve opens and cannot be controlled, it may only cause minor disruptions to production; but if an accident occurs, that’s not something to take lightly! ! !
This type of valve shouldn’t need to be operated frequently; a tool can be made and fitted over the valve stem, with chain hoists attached at both ends to open it forcefully.
Have the fitter make an extended tooling to give it a try
The solution is as follows: When a valve isn’t in use for an extended period of time, its shaft is prone to rusting and sticking. It’s necessary to replace the worm gear actuator. To open the valve, you can try making a custom socket wrench to fit over the head of the valve shaft, then loosen the two screws on the packing gland – but don’t loosen them too much (make sure there are no toxic substances or gases in the pipeline and that the pressure isn’t too high, to ensure safety). Try to rotate the valve shaft by applying force; once the shaft moves, the valve will open.
Just find a valve manufacturer to install a turbine box; it won’t cost much