Abstract: A method for operating a control valve using an HVAC actuator is described, the method comprises a circuit of the HVAC actuator executing the steps of: monitoring (S1) a rotation angle (?) associated with a drive torque (Mdrive) applied by the HVAC actuator for moving the valve member; detecting (S2) a blocking of the control valve, if the applied drive torque (Mdrive) effects a change of the rotation angle (??) which is smaller than a threshold angle (?th); upon detection of the blocking, controlling the HVAC actuator to repeatedly change the applied drive torque (Mdrive) between a first torque value (M1) and a second torque value (M2); and controlling the HVAC actuator to periodically modulate (S4) the first torque value (M1) between a third torque value and a fourth torque.

Abstract: An HVAC actuator (1) comprises a motor (12), a motor controller (13) coupled to the motor (12), and a heating apparatus (14) thermally coupled to the HVAC actuator (1). The HVAC actuator (1) further comprises a condensation controller (15) coupled to the heating apparatus (14). The condensation controller (15) is configured to monitor at least one condensation parameter, and to control the heating apparatus (14) using the at least one condensation parameter.

Abstract: A method for operating a control valve using an HVAC actuator is described, the method comprises a circuit of the HVAC actuator executing the steps of: monitoring (S1) a rotation angle (?) associated with a drive torque (Mdrive) applied by the HVAC actuator for moving the valve member; detecting (S2) a blocking of the control valve, if the applied drive torque (Mdrive) effects a change of the rotation angle (??) which is smaller than a threshold angle (?th); upon detection of the blocking, controlling the HVAC actuator to repeatedly change the applied drive torque (Mdrive) between a first torque value (M1) and a second torque value (M2); and controlling the HVAC actuator to periodically modulate (S4) the first torque value (M1) between a third torque value and a fourth torque.

Abstract: An HVAC actuator (1) comprises a motor (12), a motor controller (13) coupled to the motor (12), and a heating apparatus (14) thermally coupled to the HVAC actuator (1). The HVAC actuator (1) further comprises a condensation controller (15) coupled to the heating apparatus (14). The condensation controller (15) is configured to monitor at least one condensation parameter, and to control the heating apparatus (14) using the at least one condensation parameter.

Abstract: A butterfly valve comprises a seat ring (1), a centered valve disc (3) and a valve axis (16). The seat ring (1) and the valve disc (3) are constructed to co-operate as first and second elements of a seal for sealing a volume in which the valve axis (16) is located from internal volume of the valve. The seal is substantially a radial-force-type seal with respect to the valve axis (16). The torque for opening or closing the valve is not more than 160 Nm. The invention relates further to an actuator for a butterfly valve comprising either a voltage detection and/or a temperature and/or humidity controller and/or a safety subsystem to prevent fire in the case of fault conditions. The invention relates further to a hand crank detection system for a butterfly valve, a position indicator for a butterfly valve and an adapter between a butterfly valve and its actuator.