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How the pump of a pressure washer works

The pump: a key element in the cleaning efficiency of the pressure washer

20-03-2025

How pump pressure washer works

Pressure washers are extremely versatile tools that are indispensable in a variety of fields, from household cleaning to industrial maintenance. Their ability to remove stubborn dirt, grease residue, scale and impurities depends on one key element: the pump. This component is the beating heart of the pressure washer and the secret behind its efficiency.

Understanding how a pressure washer pump works is essential for those who want to maximize the potential of this tool and achieve long life and consistent performance. Not only does the pump determine the pressure and flow of water, but it also affects the quality of cleaning and overall wear and tear on the machine.

How Does a Pressure Washer Pump Work?

The process of generating a high-pressure water flow using a pressure washer pump takes place through three stages:

  • Suction phase: water enters the system through an inlet valve, pushed by the pressure of the running water or from a supply tank. This phase is crucial: a filter placed at the inlet protects the pump from impurities and debris, which could cause damage.
  • Compression phase: once inside the pump, the water is compressed thanks to the action of pistons or diaphragms. These mechanical components, driven by an electric or combustion engine, compress the water, drastically increasing its pressure.
  • Discharge phase: the compressed water is directed toward an outlet valve and then sent to the pressure washer's lance, where pressure turns into a powerful jet. This jet can be adjusted in intensity and shape to suit different cleaning needs.

Types of Pressure Washer Pumps

All pressure washer pumps belong to the reciprocating group and use pistons or plungers to add energy to the water.

Piston and plunger pumps operate in a very similar way. Both are positive displacement pumps that draw water through a one-way inlet valve, pressurize it, and discharge it through a one-way outlet valve.

Pressure washer pumps are specifically divided into three types based on their characteristics and use:

  • Wobble pumps: represent the most economical choice among pressure washer pumps. Their typical lifespan ranges from 200 to 400 hours and they are commonly used in units with pressure below 150 bar.
  • Axial cam pumps: usually have a service life between 500 and 800 hours and are suitable for pressure washers with pressures up to 200 bar. These pumps are known for being lightweight and efficient, although they tend to overheat during prolonged use.
  • Triplex pumps: provide the highest water pressure and can operate for thousands of hours without requiring maintenance. For this reason, they are often used in pressure washers with pressures equal to or above 200 bar. They also have replaceable valves and easily accessible heads, allowing for quick and efficient repairs. They are less prone to leaks and cool down quickly.

How to Choose the Best High-Pressure Washer Pump

When selecting a high-pressure washer pump, it’s important to consider a few aspects to identify the model that best suits your needs:

  • Pressure washer: it is essential to check which type of pump is compatible with your pressure washer. Most domestic models use wobble and axial cam pumps, while triplex pumps are more common in professional settings.
  • Pressure and flow rates: it is necessary to take into account the bar and l/min values, which indicate the water pressure and flow rate respectively, to determine the cleaning power of the pressure washer.
  • Material quality: the durability and performance of the pump depend on the construction materials. Brass or stainless steel pumps, which resist corrosion and wear, reduce maintenance needs and increase longevity, making them a long-term investment.
  • Brand reputation and customer reviews: it is advisable to choose reliable brands and read online reviews to assess the quality or shortcomings of certain models.
  • Price and budget: it's recommended to set a balanced budget between needs and quality. Although budget options may seem appealing, investing in a higher-efficiency product can prevent future repair or replacement costs.

Tips for Maintaining a Pressure Washer Pump

Proper pump maintenance is essential to ensure the long life and optimal performance of your pressure washer. Here are some practical tips:

  • Regular cleaning: remove limescale and dirt from the inlet filter daily.
  • Check oil level regularly: perform this task at least every 50 hours of use and replace the oil as indicated by the manufacturer.
  • Avoid dry running: operating the pump without water can cause irreparable damage.
  • Seal lubrication: this helps to avoid wear over time.
  • Frost protection: during the winter months, drain the water from the pump to prevent freeze damage.
  • Filter check: regularly inspect the water filter and replace it if it is damaged or excessively worn.

Find the Ideal Pump for Your Pressure Washer with Emiltec

Emiltec offers a wide range of plunger pumps from top brands, ensuring quality, reliability, and efficiency for various professional applications:

  • Pressure washers.
  • Car wash systems.
  • Firefighting systems.
  • Vehicles for sewer cleaning, drain unclogging, and street washing.
  • Fixed washing systems in the food and pharmaceutical sectors.
  • Industrial processes requiring high-pressure water for cleaning, residue removal, descaling, surface preparation, and rapid cooling.

Choosing the right pump for your pressure washer is essential to achieve the best results. The Emiltec team is at your disposal to help you select the most suitable product for your needs.

Contact us for personalized advice and discover how our products can enhance your cleaning operations.