Actuator arrangement and a method for moving a valve member into a cleaning position

An actuator arrangement being configured to be controlled by a control unit and being configured to control a flow control arrangement, the actuator arrangement comprising:

• a housing,
• a first valve stem extending along a longitudinal direction and being configured to be connected to and control movement of a first valve member of the flow control arrangement,
• a second valve stem extending along the longitudinal direction and being configured to be connected to and control movement of a second valve member of the flow control arrangement,
• wherein the flow control arrangement comprises a first and a second conduit section, each and being configured to allow a respective flow of a respective fluid, wherein the first and second conduit sections are arranged beside each other as seen along the longitudinal direction and wherein the first and second conduit sections are fluidly interconnected by a connecting opening being selectively closable and openable by a double valve formed by the first and second valve members, wherein, in a closed position of the double valve, the first and second valve members are sealingly engaging a first and a second valve seat, respectively, each valve seat extending around the connecting opening, wherein the first and second valve members are movable relative to each other to allow selective cleaning of the first conduit section, the first valve member, and the first valve seat, respectively the second conduit section, the second valve member, and the second valve seat,
• wherein in a first cleaning position, in which the first conduit section, the first valve member and first valve seat are to be cleaned, the first valve stem is configured to provide a movement of the first valve member towards the first conduit section thereby exposing the first valve seat,
• wherein in a second cleaning position, in which the second conduit section, the second valve member and second valve seat are to be cleaned, the second valve stem is configured to provide a movement of the second valve member along a longitudinal axis thereby exposing the second valve seat,
• wherein the actuator arrangement further comprises a first electrical motor comprising a first rotor and a first stator, the first rotor being rotatable about the longitudinal axis,
• wherein the first valve stem comprises a threaded portion and the first rotor is configured to grip around the threaded portion of the first valve stem such that a first rotational movement of the first rotor provides a first movement of the first valve stem in a direction opposite the longitudinal direction into the first cleaning position,
• wherein the actuator arrangement further comprises a second electrical motor comprising a second rotor and a second stator, the second rotor being rotatable about the longitudinal axis,
• wherein the second valve stem comprises a threaded portion and the second rotor is configured to grip around the threaded portion of the second valve stem such that a first rotational movement of the second rotor provides a first movement of the second valve stem along the longitudinal axis into the second cleaning position.