Accessibility to valves is the most common operation for plant folks. Valve handwheels/handles should be readily accessible and positioned to be within normal reach for operation. Access should be from permanent ladder, rolling stairs, platform, grade, or other means as required for operations, maintenance, inspection and emission monitoring.
In order to avoid knuckle injuries, minimum clearance should be 3 inch between adjacent valve handwheels, equipment and structures; and 2 inch between the back of the handwheel and insulation on the line. Additional clearance should be provided for wrench-assisted operation of valve handwheels and handles of ball-and-plug type valves.
Valve handles should be oriented such that they do not turn to restrict the access or walk-through pathway in front of the valve.
Manual operation of valve handwheels, manual gear operators, levers, or chain operators should not require application of force exceeding 80 lb. Operating valves that require a greater force to turn, or that require more than 40 turns from open or close position, should be motor-operated to reduce the likelihood of musculoskeletal and repetitive motion injuries.
Valves should be selected and installed to ensure the consistent operating stereotype of increasing flow when the actuator is turned counter-clockwise, moved from left to right, front to back or upwards.
The below figure illustrates the location of Valve Handwheels that one should consider.