Rotary valves/airlocks (rotary valves) are devices with close-fitting, revolving blades/vanes installed inside industrial equipment to control the flow of materials through a process (see Figure 1). Rotary valves are used in many industries and functions. A common example (Figure 2) is an airlock used in a pneumatic conveying system to dispense material while maintaining system pressurization. The moving blades present a significant amputation hazard hidden within the housing around the rotary valves. Often, openings at the inlet and exit of the valve housing are wide enough for workers’ hands to enter (e.g. while cleaning, troubleshooting, or maintaining), allowing contact with moving blades and resulting in amputations.
From 2015 to 2020, there were 117 amputation and laceration injuries involving rotary valves nationwide. To prevent these injuries, it is important for employers and workers to understand rotary valves’ functions, hazards, and safe use. This Safety and Health Information Bulletin (SHIB) highlights five amputation cases from a single OSHA Area Office involving rotary valves and methods to prevent worker exposure to rotary valve hazards.