What is designed to limit the output of the desiccant air dryer should the output of air increase beyond the limits of the dryer's capability?

The function of a flow limiter in a desiccant air dryer system is to regulate and prevent excessive airflow that could surpass the dryer’s designed capacity. This is vital for maintaining the efficacy of the desiccant, as it absorbs moisture from the air. When airflow increases beyond the specifications set for the dryer, a flow limiter constricts or limits the output to ensure that the system operates within its designated threshold, thereby protecting the integrity of both the desiccant material and the overall air quality delivered.

The other options serve different purposes: a pressure regulator maintains a constant output pressure regardless of variations in input pressure, while a check valve prevents backflow and ensures air flows in one direction. A bypass valve allows air to circumvent the dryer under certain conditions but does not directly limit the output based on air increases. It’s the flow limiter that specifically addresses the need to control excessive airflow to preserve the performance of the air dryer.