What is not a recognized cause for the decrease in rotary actuator speed?

A worn regulator poppet is not typically recognized as a direct cause of decreased rotary actuator speed. The function of the regulator poppet is primarily to control the pressure of the air supply to the actuator. While wear could affect the pressure regulation indirectly, it does not directly influence the speed at which the actuator operates.

In contrast, high fluid viscosity can significantly impact the speed of a rotary actuator. Higher viscosity fluids require more effort to move through the system, hence slowing down the actuator's response and overall speed.

A blocked vent port is another critical factor in decreased actuator speed. If the vent port is obstructed, it can create a buildup of pressure that prevents efficient movement of the actuator, leading to sluggish performance.

Similarly, loose actuator fittings can also result in decreased speed. Loose fittings may cause air leaks, which would reduce the pressure reaching the actuator, thus leading to slower operation as the actuator may not receive sufficient air to operate efficiently.

Therefore, understanding the functions and impacts of each component helps clarify why a worn regulator poppet is not typically listed as a primary contributor to rotary actuator speed reduction.