Air receivers are often placed without much thought, but their position relative to the dryer changes how the system performs. Wet storage before the dryer and dry storage after it serve different purposes.
Wet storage before the dryer
A receiver between the compressor and the dryer catches pulsation, cools the air and gives water a place to condense and drain. This reduces the load on the dryer and protects it from liquid slugs. It is the recommended primary position for most systems.
Dry storage after the dryer
A receiver downstream of the dryer stores already-dried air, providing a buffer close to the point of use. This helps smooth sharp demand peaks without pulling wet air through the dryer, and it keeps pressure stable at critical machines.
Using both
Many well-designed systems use both: a large wet receiver before the dryer and a smaller dry receiver near the demand. Size each for its role, fit automatic drains, and ensure the dry receiver does not mask dryer under-performance.