Patent ID: 7275557

Claim:
A method for the production of a butterfly valve having a valve body housing a valve seat engaged by a butterfly disc keyed on a shaft in order to rotate under the action of an electric motor, the shaft being coupled to a contact-free inductive position sensor provided with a rotor which is rigid with the shaft and is housed in a chamber of the valve body, and a stator which is borne by a detachable cover adapted to close the chamber and is disposed, in operation, facing the rotor, the method comprising the steps of: coupling a first end of the shaft, which is disposed within the chamber, to the rotor of the position sensor, a second end of the shaft opposite the first end being disposed in a cylindrical channel of the valve body accessible from outside the valve body; mounting the stator on the cover; completing any remaining machining operations on the butterfly valve; coupling the cover to the valve body in order to close the chamber in a substantially permanent manner; and carrying out a calibration of the position sensor with an external calibration actuator coupled to the shaft in order to dispose said shaft in a sequence of predetermined positions across the second end of the shaft.