If you have a duplex, single acting, reciprocating pump making 140 strokes/minute with a 3" diameter cylinder, and a 12" stroke with a 94% volumetric efficiency, what is the capacity of this pump?

Correct Answer: Option C — 48 gpm

Calculate capacity using: (Area × Stroke × Strokes/min × Efficiency) / 231. Area = π × (1.5)^2 = 7.068 sq in. Volume = 7.068 × 12 × 140 × 0.94 = 11,175 cubic inches. Dividing by 231 cubic inches per gallon yields approximately 48.37 gpm, which rounds to 48 gpm for standard reciprocating pump capacity calculations.