Valve Operation: Evaluation of Handwheel Actuation Techniques in Terms of Muscle Loading,Perceived Comfort,and Efficiency

Abstract

The purpose of this study was to introduce an innovative design of a valve wrench and compare it to conventional tools/methods of handwheel actuation. Four methods of handwheel actuation were evaluated, including using bare hands, regular wrench-restricted (assumes the presence of obstructions), regular wrench-unrestricted (assumes no obstructions), and modified wrench. These methods were tested on a medium-sized gate valve at two torque settings (25 Nm and 50 Nm). The methods were compared to each other, in terms of efficiency (speed), subjective ratings of perceived exertion (Borg ratings), and electromyography (EMG) activity of the left bicep and right medial deltoid. The least efficient technique at both torques was the regular wrench-restricted, and the most efficient technique was the modified wrench. At 25 Nm, the modified wrench was optimal, in that it was the most efficient and had moderately low EMG activity and Borg ratings. At 50 Nm, the regular wrench-unrestricted seemed to be the best method, having the lowest EMG activity and Borg ratings. In contrast, the bare hands technique had the highest EMG activity.