Commonly known as manual butterfly valve, butterfly valve with lever and butterfly valve with gearbox are both valves that require manual operation, but there are still differences between the two in use.

1. The lever of manual butterfly valve directly drives valve plate, switching quickly, but laborious; Gearbox butterfly valve drives valve plate by gearbox, switching slowly but effortless. Therefore, when the pressure inside the pipeline is large, it will be especially laborious to use the handle butterfly valve, and Dervos recommends you to choose the gearbox butterfly valve.

2. In engineering projects, the gearbox butterfly valves are preferred. Because in addition to saving labor, its sealing performance is also better than that of the handle butterfly valve, especially under the working conditions that require frequent switch, the gearbox butterfly valve will have a longer service life.

3. Handle butterfly valve is generally used more in small diameter (within DN200) because small diameter butterfly valve has less torque and can be opened and closed directly by hand, while gearbox butterfly valve uses gear box to drive the stem, which is more labor-saving.

When the torque of the valve stem is greater than 300N-M, use the gear box drive, otherwise, the handle drive.