Triplex pumps are a member of the reciprocating positive-displacement pump family capable of handling a wide range of corrosive, viscous or heavy fluids, from thin water-like liquids to rather viscous slurries containing large particulates. The triplex is by far the most common reciprocating pump design available in the marketplace today. There are other reciprocating displacement pumps such as the duplex and quintuplex pumps.
These pumps are intended for use in a variety of applications that require continuous and uninterrupted pumping for hours, days, or months. The term Triplex Pump refers to the number of cylinders operated either by plungers or pistons.
The term triplex pump refers to the number of plungers or pistons contained within the pump. The throws of the crankshaft are 120° apart from one another. The crankshaft contained inside the pump converts the rotational input of the drive unit into a lateral reciprocating motion.
The offset of the crankshaft throws determines the stroke of the pump. The greater the offset the greater the stroke. Attached to the crankshaft throws are the connecting rods, wrist pins, and crossheads.
The crossheads are responsible for maintaining and guiding the lateral movement of the connecting rod within the power frame of the pump. It is the straight controlled lateral movement of the crosshead attached to the plunger adapter, plunger, or piston that actuates the suction and discharge valves located in the fluid end of the pump.
The pump must rotate 360° to complete one revolution of the pump. Some pumping applications may run as fast as 600 RPM, or 10 revolutions per second, it is the speed along with 120° separation of the crank throws that provide the smooth operation of the triplex pump.
Triplex pumps prove indispensable in many key applications. The size of a triplex pump can determine its use, for example, small triplex pumps can be used in industrial and water jetting applications. Industrial pumps can be used in oil line pumping, mine dewatering, chemical & petroleum products transfer, and well servicing. Water jetting pumps can be used in surface preparation, hydro demolition or hydrostatic testing.
There are multiple applications for large triplex pumps in oilfield operations. For example, large triplex pumps are often used for drilling, hydraulic fracturing, cementing, and descaling operations.
Triplex drilling pumps can be powered by single or multiple sources. In most cases, almost all drilling pumps are powered by one or more electric motors.
On a triplex frac pump, it is common to use a single power source. In most cases, frac pumps are powered by a diesel engine. However, it’s not uncommon for fracking companies who have developed frac equipment for residential areas to use electric fleets. These units are significantly quieter and produce significantly less harmful emissions.
So why do frac pumps and drilling pumps run on different power sources? It all comes down to operational cost and equipment mobility.
Whether pumping water, oil, gas, slurry or chemicals, the triplex pump is a dependable piece of equipment that has stood the test of time.