What happens when you shut the fluid discharge of an air-operated reciprocating pump?

When the fluid discharge of an air-operated reciprocating pump is shut, the flow of fluid exiting the pump is stopped. This condition leads to a situation where the pump continues to operate, but because there is no place for the fluid to go, the pressure within the pump system begins to rise. However, it's important to note that eventually, the rising pressure can lead to a stall condition where the pump may not be able to perform its intended function effectively.

In this scenario, the pump's mechanism is designed to function based on a proper balance of discharge and suction. When discharge is blocked, the air pressure driving the piston can create too much resistance, which can cause the pump to stall due to insufficient hydraulic flow and the inability to complete a full cycle of operation. Therefore, the correct answer emphasizes that the pump, unable to discharge fluid, will stall under these conditions.