In Oil Fields, Pumps are used to pump the Drilling Fluids “OBM or WBM” into the well-bore through the Drill String. The number of used pumps is based on the required flow or pumping rate of drilling fluid. At least, there must be one Primary pump and one Back-up pump to be used in case of breaking down. There are mainly two types of these pumps:
a) Duplex Pumps consisting of Two Pistons “Cylinders” —-> (Double Acting “Two Inlets-Two Outlets”)
b) Triplex Pumps consisting of Three Pistons —-> (Single Acting”One Inlet-One Outlet)
This Gif shows the difference in acting between One way piston “Single acting” used in Triplex Pumps and Two Way Piston “Double Acting” used in Duplex Pumps. The left one is the single acting piston while the other one is the double acting piston.