Faulty electric ball valve
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The natural gas electric ball valve gets stuck in both manual and automatic modes; is it a fault with the electric actuator or a problem with the ball valve body?
Remove the electric actuator and operate the ball valve manually to diagnose the fault.
The valve is malfunctioning: the ball of the ball valve and its sealing surfaces are worn, or there are debris on those sealing surfaces. Disassemble it and clean it; apply some oil to the valve stem, and that should resolve the issue.
First, turn it on and off manually to see if there is much resistance; if the resistance is high, it’s a problem with the valve. If the resistance isn’t high, check whether the torque setting of the actuator is appropriate. If the valve resistance is too high, the valve can be cleaned. You mentioned that the manual resistance is also high; it’s likely a problem with the valve itself.
Electric actuators have a relatively high chance of failing, but this can only be determined after inspection.........
Let me understand – you mean that the valve worked well when powered electrically at first, but after some time, both the electric and manual operation methods stopped working, right? If that’s the case, it’s a problem with the valve body. Are there any solid impurities in the natural gas flowing through the pipeline? Generally, there should be no solid impurities in natural gas. If the valve no longer functions properly and cannot be opened either manually or automatically, it’s likely that the valve core and seat are stuck together. It can be taken down on-site for cleaning.
The manual and automatic modes used to work fine, but suddenly they stopped functioning properly. Now, when trying to operate them manually to turn them on or off, it seems like they don’t move at all, as if something is blocking them.
Well, in that case it’s a problem with the valve body; it has nothing to do with the actuator. If the actuator isn’t able to open but can be operated manually, then it’s indeed a problem with the actuator. It’s recommended to remove the ball valve and clean it on-site – that should solve the issue. Also, I see that the medium used is natural gas; are your pipes new? Natural gas generally does not contain any solid materials. If it’s stuck, could it be because the pipes are new? After the pipes were welded, the weld slag wasn’t removed, and now that slag is stuck inside the valve. I guess that’s the case; otherwise I have no idea. There must be a problem with the valve body – let’s take it apart...
The safest approach is to remove the actuator and use a manual switch to determine the scope of the fault. The theoretical analyses and guesses of the above-mentioned individuals are useless. Diagnosing faults in such self-control valves is quite challenging.
Electric valves all come with a handwheel for manual operation. 1. First, turn the handwheel slightly to check the level of resistance. 2. If the force is strong, disconnect the motor head from the valve body. Move it alone. The source of the fault was immediately identified. If the medium is generally a dry gas, it is recommended to increase the actuator torque by 1.5 times.