Understanding The Difference Between Axial And Triplex Pumps

Posted on: 29 May 2019

The most important part of any commercial pressure washer is the pump. This is the key part of the machine that takes the plain old water and pumps it up to the high pressure that's necessary to get real work done. When choosing a washer for high-intensity jobs such as industrial equipment cleaning, it is especially important to select one with a pump that is up to the task. The two types of pumps commonly found in industrial pressure washers are axial and triplex pumps. Both are excellent designs, but each comes with its own set of advantages and disadvantages.

Working Direct: Axial Cam Pumps

Axial pumps are a variety of direct drive pump. Direct drive pumps work exactly as you might expect from the name. These pumps are connected directly to the pressure washer motor, usually by a simple shaft which fits over the motor's driveshaft. This is a simple, reliable, and effective way to transfer power from the engine to the pump. It also means that the pump always operates at the same speed as the engine since there is no intervening hardware to stop the motor's output up or down. As the driveshaft spins, it turns a cylinder block filled with pistons which pull water in on their upwards stroke and expel it on the downward stroke.

The primary advantage of axial pumps is that they are simple, highly compact devices. Axial pump washers are generally more compact and lighter than the alternatives. Depending on the design of the axial pump, the flow rate may or may not be adjustable, but the speed is always fixed. Since the pump rotates with the engine drive shaft, it is never possible to increase or decrease the pump's rotational speed. This can potentially lead to the cylinder seal wearing out more quickly.

Long Life: Triplex Pumps

The other type of pump commonly found in high-end, commercial grade pressure washers is the triplex pump. Unlike the axial cam pump, the pistons in the triplex pump are not connected directly to the output shaft of the engine. Instead, a triplex pump makes use of a crankshaft with connecting rods to drive the pistons. The pistons draw water into the cylinders as they move upward and then push the water out on the downward stroke.

Triplex pumps are usually more expensive upfront, but their cost can be offset since they generally offer an exceptionally long life. Their higher complexity means that they are not quite as maintenance free as simpler pump types, but with proper maintenance, they will provide years of service. Triplex pumps are also more efficient than axial cam pumps, which can translate to lower overall operating costs throughout the life of the pump.

Despite the advantages of triplex pumps, however, both of these pumps are capable of delivering the flow rates necessary for high-end industrial cleaning operations. Choosing the right one for your company is largely a matter of selecting a pump that fits within your budget and offers the exact specifications that you required.

For more information on high pressure pumps, reach out to a local retailer.