Valve closure system and valve closure assembly having torque limiting

An assembly for turning an external handle of a tank dome valve about a vertical axis, the assembly comprising:

• a mounting for removably mounting the assembly on a tank dome,
• an adapter operated by a motor acting through a torque limiter for engaging the valve handle and turning the handle when the motor operates the torque limiter, and
• a positioning mechanism for selectively positioning the adapter relative to the mounting to establish a spatial relationship of each to the other for enabling the mounting to be placed at a desired location on the dome and the adapter to engage the valve handle, wherein the positioning mechanism comprises three degrees of freedom of motion for establishing the spatial relationship of the adapter to the mounting.

A method of associating a valve operating assembly with a fluid-containing tank for enabling an adapter that is operated by a motor of the valve operating assembly acting through a torque limiter to turn an external handle of a valve on the tank about an axis of turning while a mounting of the assembly is supporting the assembly on the tank, the method comprising:

• positioning the mounting relative to the torque limiter and adapter via a positioning mechanism of the valve operating assembly that has two degrees of freedom of motion in a plane of reference that is perpendicular to the axis of turning to establish a spatial relationship for placing the adapter in engagement with the valve handle and for placing the mounting at a desired location on the tank.

A method of associating a valve operating assembly with a fluid-containing tank for enabling an adapter operated by a motor of the valve operating assembly acting through a torque limiter to turn a valve on the tank about an axis of turning while a mounting of the assembly is supporting the assembly on the tank, the method comprising:

• positioning the mounting relative to the torque limiter and adapter via a positioning mechanism of the valve operating assembly that has three degrees of freedom of motion to establish a spatial relationship for placing the adapter in engagement with the valve handle and for placing the mounting at a desired location on the tank.

A method of associating a valve operating assembly comprising a mounting, a positioning mechanism, and an adapter operated by a motor acting through a torque limiter, with a dome of a fluid-containing tank comprising a valve having a handle that is external to the tank and an upright wall spaced horizontally from the valve handle for enabling the adapter to engage the valve handle and turn the handle about an axis of turning while the mounting is supporting the assembly at a desired location on the dome in horizontally spaced relation to the valve handle, the method comprising:

• disposing the valve operating assembly vertically over the dome, lowering the assembly onto the dome, and causing the positioning mechanism to relatively position the torque limiter so as to place the adapter in engagement with the valve handle and to relatively position the mounting so as to place the mounting at a desired location on the upright wall.