Method of and apparatus for operating an actuator

An apparatus for closing a valve in a pipeline comprising:

• an actuator connected to an actuating element of said valve;
• said actuator driving said valve from an open position to a closed position by:
• closing said valve at maximum actuating speed during a first closing phase until said valve reaches a predefinable position;
• closing said valve during a second closing phase such that the actuating speed of the actuating element of the valve is reduced continuously and steplessly with a predefinable gradient until said actuating speed is reduced to a predefinable constant speed value;
• and
• closing said valve during a third closing phase by maintaining said predefinable constant speed value until said valve is completely closed.

A combination comprising:

• a pipeline;
• a valve in said pipeline;
• an actuator connected to an actuating element of said valve;
• said actuator driving said valve from an open position to a closed position by:
• closing said valve at maximum actuating speed during a first closing phase until said valve reaches a predefinable position;
• and
• closing said valve during a second closing phase such that the actuating speed of the actuating element of the valve is reduced continuously and steplessly with a predefinable gradient until said actuating speed is reduced to a predefinable constant speed value;
• and
• closing said valve during a third closing phase by maintaining said predefinable constant speed value until said valve is completely closed.

A method of operating an actuator for closing a valve in a pipeline, said pipeline for having a liquid flowing therethrough, the valve having a movable actuating element which is operated by the actuator, comprising:

• closing the valve at maximum actuating speed during a first closing phase until said valve reaches a predefinable position;
• and
• closing said valve during a second closing phase such that the actuating speed of the actuating element of the valve is reduced continuously and steplessly with a predefinable gradient, said closing of said valve during said first closing phase and during said second closing phase avoiding pressure surges and resonances in said liquid;
• wherein the actuating speed in said second closing phase is reduced to a predefinable constant speed value and said method further comprises closing said valve during a third closing phase in which said predefinable constant speed value is maintained until said valve is completely closed.

An apparatus for closing a valve in a pipeline, said pipeline for having a liquid flowing therethrough, comprising:

• an actuator connected to an actuating element of said valve;
• said actuator driving said valve from an open position to a closed position by:
• closing said valve at maximum actuating speed during a first closing phase until said valve reaches a predefinable position;
• and
• closing said valve during a second closing phase such that the actuating speed of the actuating element of the valve is reduced continuously and steplessly with a predefinable gradient,
• said closing of said valve during said first closing phase and during said second closing phase avoiding pressure surges and resonances in said liquid;
• wherein said valve actuating speed in said second closing phase is reduced to a predefinable constant speed value and further comprises closing said valve during a third closing phase in which said predefinable constant speed value is maintained until said valve is completely closed.

A combination comprising:

• a pipeline for having a liquid flowing therethrough;
• a valve in said pipeline;
• an actuator connected to an actuating element of said valve;
• said actuator driving said valve from an open position to a closed position by:
• closing said valve at maximum actuating speed during a first closing phase until said valve reaches a predefinable position;
• and
• closing said valve during a second closing phase such that the actuating speed of the actuating element of the valve is reduced continuously and steplessly with a predefinable gradient,
• said closing of said valve during said first closing phase and during said second closing phase avoiding pressure surges and resonances in said liquid;
• wherein said valve actuating speed in said second closing phase is reduced to a predefinable constant speed value and further comprises closing said valve during a third closing phase in which said predefinable constant speed value is maintained until said valve is completely closed.