Butterfly valve — how to distinguish between wheel-type and handle-type in the model number?
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The code for valve actuation methods states that this code is omitted for handwheel and handle actuation. If a handwheel type is required, how should it be indicated in the material list? Also, what’s the difference between a handwheel and a worm gear?
The choice between a handwheel or a handle is determined based on the pipe diameter or the nominal pressure of the valve, in order to determine the torque required to open it; this is usually decided by the manufacturer. Of course, you can also put forward your own requests!
Butterfly valves open at 90 degrees; if the model does not specify otherwise, manual operation via a handle is generally assumed. If high torque is involved, then the use of a gearbox or some other driving mechanism should be considered. A handwheel is used for valves that can rotate 360 degrees. This is all I have learned so far; it is for reference only.
Small valves, priced under 100, and most of them have soft seals; for applications with modest requirements, handles are commonly used. Butterfly valves with hard seals seem to all use worm gear mechanisms.
Butterfly valves that come with a handwheel usually use worm gear transmission; handwheel types are generally used for 360° rotation, whereas butterfly valves operate with a 90° rotation.