Reciprocating Pump Flow, i.e. Triplex and Quintaplex Pumps

Diameter / 2 = Radius
Radius² X Pi = Area
Stroke Length X Area = Cubic Inches per Stroke
Cubic Inches per Stroke X Number of Pistons = Cubic Inches per Cycle
Volume per Cycle / 231 = Gallons per Cycle
Gallons per Cycle X RPM = Gallons per Minute, "GPM"
Gallons per Minute X 24 X 60 = Gallons per Day, "GPD"
Gallons per Day / 42 = Barrels Per Day at 100% Efficiency, "BPD"

Stroke Length, "Stroke"
Bore Diameter, "DIA"
Pistons, "P"
Revolutions per Minute, "RPM"
Efficiency, "EFF"