The water pump is the core part of a high-pressure cleaning machine. The high-pressure pump is used to drive clean water to achieve sufficient pressure for operation. When purchasing a high-pressure cleaning machine to deal with difficult working conditions such as industrial equipment cleaning, you need to pay attention to the performance selection of the pump.
In pressure washing industry, two types of commonly used pumps are axial pump and triplex pump. As a professional pressure cleaning machine manufacturer, BISON has an in-depth understanding of high-pressure washer pumps. In this post about axial pump vs triplex pump, BISON will show the significant differences between these two types of pumps.

Axial pumps

There are numerous direct drive pump options for axial pumps. Direct drive pumps function precisely as their name would imply. These pumps are directly connected to the pressure washer motor, typically via a straightforward shaft mounted on the motor drive shaft. It is an easy, dependable, and effective method of moving engine power to the pump. This implies that no hardware stops the motor from increasing or decreasing power, so the pump always operates at engine speed. A cylinder block with a piston that draws in water on the upstroke and releases it on the downstroke is rotated by the drive shaft.
Axial flow pumps’ primary benefit is their simplicity and extreme compactness. Axial pump washers are typically lighter and smaller than alternatives. The speed of an axial flow pump is fixed, while the flow can be adjusted based on its design. Changing the pump rate is impossible because it revolves around the engine drive shaft. Cylinder seal wear may increase as a result of this.
How does an axial pump work?
An impeller in an axial pump typically has three or four vanes. Vanes are positioned so that, instead of flowing radially (at a 90-degree angle to the post), the pumped fluid flows axially or in the direction of the shaft. An electric motor typically drives the impeller. When the liquid is pumped, very little head is produced by the impeller blades’ axial direction.
Compared to other centrifugal pump types, axial flow pumps have a much lower head output of only 10 to 20 feet. They can have the highest centrifugal pump flow rates, reaching several hundred thousand gallons per minute.
Because axial flow impellers resemble marine propellers, propeller pumps are named after them. Specific arrangements allow for adjusting flow and head through modifications to the impeller blade pitch.
When compared to other types of pumps, axial flow pumps exhibit completely different performance characteristics types. Compared to other centrifugal pump types, they have a much steeper head-to-capacity curve despite producing very little head at their typical operating point. Three times the lead at the pump’s optimal performance point is the closed (zero flow) head. In addition, the required horsepower increases as flow decreases, with the highest horsepower consumption at shutdown (zero discharge). This contrasts with the tendency of radial flow pumps, which require more horsepower at higher flow rates.
Axial flow pump applications
Applications needing very high flow rates and low pressures employ axial flow pumps. In power plants, they can be employed as circulating water pumps. They are also frequently used to distribute significant amounts of liquids to vapors in the chemical industry. They are helpful in flood drainage applications where large volumes of water need to be moved over short distances, such as on levees. These applications are less typical than radial flow pumps, so there are fewer axial flow pumps than radial flow pumps.
Advantages of axial pump
- These dynamic pumps are ideal for high flows and low heads.
- The effect of fluid circulation is less severe for axial flow pumps.
- Axial flow pumps are easy to configure for efficient operation for low flow and high head.
- These are the smallest of several common types of pumps.
- They are simple to use and handle due to their small size
Disadvantages of axial pump
- These pumps are expensive.
- These pumps cannot handle viscous liquids.
- There are better choices for applications that require high head or pressure.

Triplex pumps

The triplex pump is another type commonly found in high-end commercial-grade pressure washers. Unlike an axial pump, a triplex pump’s piston is not directly attached to the engine’s output shaft. Instead, the piston in triplex pumps is driven by a crankshaft and connecting rod. Water is drawn into the cylinder and forced downward as the piston rises.
Triplex pumps typically have a higher initial cost, but their cost can be offset by the fact that they usually offer a much longer service life. Due to their high complexity, they require more maintenance than straightforward pump types, but they can last for many years with the proper care. Additionally, triplex pumps are more efficient than axial pumps, which can result in lower total operating costs during the pump’s lifetime.
How do triplex pumps work?
Moving fluids with a single piston or plunger pump is incredibly effective. However, the piston or plunger’s reciprocating motion can lead to severe cyclic loads on the pump drive mechanism and noticeable pulsations in the discharge pressure, which can cause bearings and other mechanical components to fail too soon. On the other hand, using multiple plungers or pistons results in a smoother flow, less pressure pulsation, less fatigue on the pump’s mechanical parts, and an increase in the pump’s overall efficiency. Moreover, flow and pressure are raised.
A standard AC motor drives triplex pumps. It comprises a crankshaft and connecting rod assembly that works similarly to an internal combustion engine to translate the motor shaft’s rotation into the reciprocating motion of a piston or plunger. Remember that specific plunger and piston pumps contain more than three cylinders. As is familiar with all positive displacement pumps, each pump cylinder typically has a set of check valves, one on the input and one on the output.
Applications of the triplex pump
Small triplex pumps with plungers, sometimes called power washers, are often used as high-pressure wash pumps. These can be used at car washes, commercial and industrial wash stations, and farms. Smaller versions are also utilized in homes as electric washing machines.
The main applications for larger versions, such as piston and plunger styles, are oil drilling and well servicing. Every variety can manage thick, sticky and corrosive fluids very effectively, including abrasives, slurries, and liquids containing large amounts of solids.
Advantages of triplex pumps
- The pump’s end is more accessible.
- Because there is less turbulence at the pump’s output, there are fewer ripples than with a tandem pump.
- High pressure is applied to vast volumes of fluid.
- Able to manage viscous liquids.
Disadvantages of the triplex pump
- High upfront cost.
- Maintenance could be more friendly.
- It is usually large, so it isn’t easy to handle.
Pressure washer pumps are complicated, especially if you need to learn about them. When your pressure washer pump breaks, there’s no need to worry. With the information we’ve researched for you in this article, you’ll be able to face your next pressure washer or pressure washer pump purchase without a doubt.
A direct drive pump that spins at the same speed as the engine is called an axial pump. Although they produce much hydraulic power and sound pressure, axial flow pumps wear out more quickly than triplex pumps. For most do-it-yourself washing jobs, an axial pump washing machine is appropriate.
Triplex pumps are heavy-duty displacement pumps that operate by contracting and expanding rather than rotating; they are found in many commercial-grade pressure washers. When used simultaneously, triplex pumps are typically more durable than axial pumps; however, washers for this type of pump will cost more.
Despite the triplex pump’s advantages, both pumps can provide the flow needed for sophisticated industrial cleaning operations. Selecting a pump that meets your needs and falls within your budget is the first step in choosing the best one for your business.
FAQs About axial pump vs triplex pump
An axial pump will typically last 2-3 times longer than a wobble pump, which means you can expect 500 to 800 more hours of use. Although axial pumps are better designed than submersible pumps, they still experience more friction than triplex-type pumps.
No, they are not. Some say they are universal, but they only work with the majority.
You should always check the pump dimensions against your pressure washer to ensure they are compatible. You should also check PSI and GPM, as mixing different species will yield poor results.
You cannot replace an axial pump with a triplex. But it is possible to replace an axle with a better-designed axle. As long as the pump can fit, it should work.
Do not attempt to upgrade from axial to triplex. The pump is not going to fit, either. If you want a triplex pump, you'll need to buy a pressure washer that uses it.
There are two main pump types: Axial: Small pump with a stirring plate system ideal for many light and medium duty applications. Triplex: A large pump with a crankshaft and piston system that provides high power and long life is used in medium- and heavy-duty applications.
It depends on the damage. Triplex pumps are easy to repair because of the parts available. But you should attempt this only if you are knowledgeable. Axial pumps are difficult to repair. Once it's damaged, you're better off purchasing a replacement.