An actuator stopped moving. What is not a likely cause?

In the context of troubleshooting pneumatic actuators, each potential cause must be assessed based on how it affects actuator functionality. A check valve that is stuck open would typically allow fluid to flow freely in one direction, which should not prevent an actuator from moving; instead, it may contribute to unintended motion or keep the actuator in a default position.

In contrast, worn seals, a blocked inlet port, and a load increase are situations that would more commonly lead to an actuator failing to move. Worn seals can cause a loss of pressure and efficiency, while a blocked inlet port would restrict the air supply needed for movement. An increase in load might exceed the actuator's capacity, preventing it from moving altogether.

Thus, recognizing that a stuck open check valve does not align with typical causes of movement failure provides clarity as to why it is not a likely cause in this context.