Revise API Standard 599 Metal Plug Valves—Flanged, Threaded, and Welding Ends as follows:
a. State that there have been multiple incidents in which workers have inadvertently removed pressure-retaining components from plug valves while workers were attempting to remove the valve’s actuator or gearbox.
b. Recommend that facilities using plug valves establish written procedures detailing the correct way to remove the plug valve actuator or gearbox for each specific plug valve design at the facility.
c. For existing plug valves, require facilities to clearly mark all pressure-retaining components (for example, with paint, accompanying warning signs, etc.). Work with ASME and VMA to ensure a consistent methodology is specified across both API and ASME standards.
d. Require that new plug valves be designed, consistent with Prevention through Design principles, to prevent the inadvertent removal of pressure-retaining components when removing the actuator or gearbox. Evaluate past plug valve incidents, and the associated plug valve designs involved in those incidents, when formulating a new plug valve design. Work with ASME and VMA to ensure a consistent methodology is specified across both API and ASME standards.