To increase the delivery volume of a reciprocating pump, what modification is typically made?

Increasing the delivery volume of a reciprocating pump can be effectively achieved by lengthening the piston stroke. The stroke length determines how much fluid the pump can displace with each cycle. A longer stroke means that the pump can draw in and push out a greater volume of liquid during each pumping cycle, thus enhancing the overall throughput of the system.

In a reciprocating pump, the piston moves back and forth in a cylinder, and as it moves forward, it displaces a volume of liquid. By extending the stroke, the volume of liquid displaced in each cycle increases, leading to a higher delivery volume. This is particularly useful when the application requires the handling of larger flow rates without changing other mechanical components or the operational speed of the pump.

The other options involve adjustments that may not directly correspond to an increase in delivery volume. For instance, changes to the inlet or discharge valves can affect pressure and flow dynamics, but they do not fundamentally alter the volume per stroke as lengthening the piston stroke does. Thus, while they may have their relevance in pump operation, they do not specifically address the modification needed to maximize delivery volume in the same manner as lengthening the stroke.