Pressure washer

Performances displayed in pressure and flow

Water Pressure/Flow: Cleaning Impact
• Impact is the force with which the water hits the surface to be cleaned. It gives an indication of the cleaning efficiency.
• Water flow influences the impact value more than pressure.
• Calculation formula: IMPACT=(0.024xl/min)x bar / 0.981
Example: A machine of 180 bars/1000 l/ha an Impact coefficient of 5.4
=> If we increase the pressure by 10% , we obtain 198 bars with an impact of 5.7, i.e. + 5.5% efficiency
=> On the other hand, if we increase the flow rate by 10% , we obtain 1100 l/h with an impact of 6.0 or + 11.1% efficiency
So it is clear that often manufacturers from a marketing point of view put pressure forward but it is much less important than the water flow in terms of performance.

Water Pressure / Flow: Washing Impact vs. Washing Distance
• If we increase the distance between the surface to be cleaned and the HP nozzle, we reduce the impact force but increase the cleaned surface .
- Recommended cleaning distances:
-> 5 to 10 cm for stripping very resistant surfaces (stone, raw metal, etc.)
-> 10 to 15 cm for washing resistant surfaces (painted metal, concrete, tar, etc.)
-> 10 to 20 cm for washing fragile surfaces (plaster, wood, etc.)
-> +20 cm for rinsing

Water Pressure / Flow: Washing Impact vs. Washing Distance - Performance
-> Performance is the most important point to optimize cleaning costs and limit machine wear:
-> The higher the water flow, the higher the efficiency.
- Reduction of working time
- Reduced machine wear
-> If we increase the distance between the surface to be cleaned and the HP nozzle , we reduce the impact force but increase the surface area cleaned.
Explanation :
-> A high-pressure cleaner with a water flow rate of 500l/h has the same cleaning impact at 6 cm from the
surface than 1200 l/h at 22 cm from the surface.
-> Thanks to the standard nozzle angle of approximately 20°, the cleaning width increases from 2.7 cm to 10 cm, i.e. 300% more performance !

Water Pressure / Flow: The Right Nozzle for the Right Application
-> It is not possible to increase the working pressure of an NHP
-> On the other hand, it is perfectly possible to reduce the pressure by increasing the caliber of the nozzle
-> At the same time, increasing the spray angle of the nozzle will increase the efficiency
? Adaptation of pressure to customer needs
? Reduced working time with a wide jet nozzle
? Enhanced security for fragile surfaces

How to choose your professional high pressure cleaner?

In view of all the previous explanations you will now be able to better understand the figures given on high pressure cleaners. As we have seen, it is widespread among high pressure cleaner users that it is the pressure in bars that is decisive. This is a shortcut and of course you will have now understood many other parameters will give you the real performance and impact force of your high pressure cleaner.
The parameter that is often forgotten is the water flow rate.
Indeed, it is the multiplication of the pressure and the flow rate of the high-pressure cleaner that will give a real value of the performance through the impact force calculated above. Thus a high pressure linked to a low flow rate will have no effectiveness.
Cleaning with a high-pressure cleaner can save you up to 75% of your time.
Water saving: in fact the flow rate of a water tap can reach up to 2500 l/h, a high-pressure cleaner provides between 500 and 1300 l/h.
The choice of a high-pressure cleaner is also made in relation to its power supply: single-phase 230 Volt high-pressure cleaner (Pay attention to the available amperage), 400 Volt three-phase equipment (specify with or without neutral), autonomous high-pressure cleaner (petrol or diesel engine).

Key parameters in summary

- Pressure. It indicates the force of the water jet at the outlet of the lance or at the outlet of the pump according to the technical sheet and is expressed in bars. A high pressure makes it easier to clean stubborn dirt. However, this selection criterion for a professional high-pressure cleaner does not go without a second parameter, which follows which is the flow rate.
- The flow rate. This data is expressed in liters per hour , and indicates the volume of water projected . The pressure alone is nothing if the flow rate does not follow. When the flow rate is high, it will allow large surfaces to be cleaned more efficiently. The impact force is the result of its pressure and flow rate values as explained above.
- The installation present on the construction site . Many models operate with electrical energy, and can be single-phase or three-phase. It is therefore necessary to take into account the installation available on the construction site, and check which connections are possible. Some locations are devoid of any current. It will then be necessary to opt for a professional thermal high-pressure cleaner, operating on petrol and therefore autonomous in terms of energy.
- The budget. Inevitably, this argument is essential. Depending on the financial envelope allocated to the acquisition of a high-pressure cleaner, the possible models are more or less numerous. Don't forget Voussert's promotions which regularly allow you to buy a professional electric or thermal high-pressure cleaner at a knockdown price.

The different types of professional pressure washers

Professional pressure washers come in two distinct types. The first runs on electric power, while the second, thermal, requires gasoline. What are the advantages and disadvantages of these respective models?

Electric pressure washers

When it comes to professional high-pressure cleaners, the electric version, whether single-phase for standard models or three-phase for more powerful models, is the benchmark. Powerful and versatile, it is also more environmentally friendly than its thermal counterpart. On the other hand, the requirement to connect it to an electrical outlet somewhat reduces its appeal. It is essential that the site has such an installation to use the electric high-pressure cleaner. In addition, you must pay attention to the amperage required, particularly when starting the device. Indeed, the most powerful single-phase high-pressure cleaners require a socket with a minimum of 16 Ah . The same goes for three-phase where the installation and amperage must be adapted to the cleaner. It is therefore imperative to check the adequacy between the amperage of the socket and your device.

High pressure thermal cleaners

A professional high-pressure cleaner with a thermal engine is essentially distinguished by its internal combustion engine, using gasoline or diesel to operate. Their autonomy is greater than models operating with electric energy, because these thermal devices do not need a power outlet to be handled. However, the noise and pollution they generate can dissuade the purchase of these models. The main criterion for purchasing a thermal model is above all autonomy and mobility while maintaining large cleaning capacities. This type of model is preferred in certain professions such as construction, agriculture or mobility and autonomy are predominant.

Care and maintenance

The maintenance and upkeep of a professional high-pressure cleaner will not be exactly the same depending on whether the model considered is thermal or electric. However, certain elements overlap between these two equipment.
So, in either case, the maintenance of a high-pressure cleaner must be carried out as soon as its use is finished. It will then be important to rinse the cleaner with clean water, in order to eliminate any residue in the system. The detergent water tank or the cleaning product must also be emptied, if the model has this tank. It is also recommended to clean dirt and cleaning product residue with a damp cloth. Furthermore, in the case of a thermal high-pressure cleaner, let the engine cool down before storing it.
Maintaining a thermal model requires more attention. In this regard, it will be important to check:
- The need to change the fuel, according to the manufacturer's recommendations;
- The engine oil level, in order to top it up if necessary;
- The condition of the spark plug, with a view to replacing it if it is damaged.