The capacity of a reciprocating compressor will:

The capacity of a reciprocating compressor is directly influenced by the suction pressure. When the suction pressure increases, the compressor can draw in more refrigerant vapor more easily. This increase in the density of the refrigerant vapor at higher suction pressures allows the compressor to move a greater volume of refrigerant during each cycle, thereby increasing its overall capacity.

In a reciprocating compressor, the compression process relies heavily on the pressure differential between the suction and discharge sides. Higher suction pressure means that there is less work required for the compressor to draw in the vapor and it can compress larger quantities more efficiently. Consequently, the capacity of the compressor improves as the suction pressure rises.

The other factors mentioned, such as leaky valves or aging of the compressor, could disrupt the efficiency or functionality of the compressor but do not contribute positively to its capacity. A leaky valve typically results in loss of refrigerant and reduces the effective capacity, while aging could lead to wear and inefficiencies, also causing a decline in performance over time. Therefore, the most accurate statement regarding the capacity of a reciprocating compressor is that it will increase with an increase in suction pressure.