Abstract: Valve controllers and methods of their use are described. Valve controllers of the type described herein can be used to operate valves that are out of manual reach by the operator. One embodiment of a valve controller includes proximal and distal controller heads connected to each other via a hollow elongate shaft. Each of the proximal and distal controller heads includes a rotatable pulley wheel that is connected to a valve control engagement member for engaging a handle of a valve operable to shift the valve from a first position to a second position. The rotation of the proximal and distal pulley wheels, and thereby the proximal and distal engagement members, is coupled via a cord that runs through the hollow elongate shaft and around a circumferential portion of each pulley wheel.

Abstract: Methods and apparatus for positioning an orifice plate within a body having a straight flowbore. One embodiment includes a carrier supporting the orifice plate and a drive member operable to engage the carrier and move the carrier along a first axis perpendicular to the flowbore. The drive member is also operable to limit the movement of the carrier along a second axis perpendicular to the flowbore and perpendicular to the first axis. A pin is operable to engage the carrier so as to limit movement along the first axis.