What component on the discharge side of a reciprocating feed water pump provides a constant flow?

The component on the discharge side of a reciprocating feed water pump that provides a constant flow is the air chamber.

An air chamber, also known as an accumulator, serves to smooth out the pulsations caused by the reciprocating action of the pump. As the pump operates, it creates pressure fluctuations that can lead to intermittent flow. The air chamber contains compressed air, which acts as a cushion. When the pump delivers water, the air expands to absorb the surge, helping to maintain a steady and constant flow rate. This results in a more uniform discharge that is less prone to pressure spikes, which is critical in systems requiring consistent output, such as in boiler feed water systems.

In contrast, a pressure regulator is designed to maintain a certain pressure level rather than constant flow; a check valve ensures that flow only goes in one direction without affecting the flow rate; and a flow meter measures the flow but does not influence or stabilize it. Hence, the air chamber is the key component that addresses the need for constant flow in a reciprocating feed water pump system.