Issue
Unreliable documentation
Environment
Butterfly valve
Cause
Replacement
Resolution
The MF20 / MF40 actuator data sheets are supposed to be updated in regards to the use on old TRV-S valves.
Basically the standard MF40 fits to the TRV-S DN150-200, but the unique MF20-R fits to everything else.
So you need to know the valve.
No other adaptors are required.
Click here for data sheet