Published : 07/26/2018 10:31:12
Categories : Harrison Hire & Sales Posts
We sell pressure washers, and every pressure washer comes with a high pressure hose, and a trigger gun with a lance. At the end of every lance is a small nozzle that has a massive impact on the performance. What nozzle you require depends on a number of factors, including what you want to clean. First of all, we need some background knowledge about pressure washers.
All about bar and water flow…
The power a pressure washer pump produces depends on how much pressure it produces, and also by how much water it can pump. Pressure is measured in Bar (or in the USA Pound per Square Inch is often used. 1 Bar = 14.5 psi). Water flow is measured in LPM (Litres Per Minute) or Litres Per Hour. Higher pressure will provide a better cleaning action whereas a higher flow is preferable for rinsing. A lower flow rate on a machine means that it will take longer for dirt to be washed away.
Big brands like Karcher and Nilfisk often give the pressure (not bar) and water flow in the model name. For example, Karcher use model names like HD 5/12 referring to a flow rate of 500l/h and a bar of 120, Nilfisk use model names like MC 4M-140/620, where 140 refers to the pressure and the 620 refers to the water flow. Another consideration is that some manufacturers quote max pressure as opposed to operating pressure. Make sure you look carefully at the spec so that you can compare like for like!
Now back to nozzles…
A nozzle code is made up of two important numbers: the angle, and the orifice diameter. The orifice diameter must suit the water flow and pressure of your machine. The angle you choose depends on the job you want to do.
25075 is made up of 25° fan and 075 which is the size of the hole.
00020 would be a 0° pencil jet with a 020 orifice.
Ask a pressure washer expert for advice on matching your machine to the correct nozzle. It is not possible to increase the pressure of a machine by using a smaller nozzle, in fact a smaller than recommended nozzle will reduce water flow and impact on rinsing performance. Additionally, you can cause damage to your equipment if constantly used with a nozzle that is too small. Take a look at our nozzle guide for help finding the right one for your high pressure cleaner:
If you want to reduce pressure slightly, or maybe don’t have the exact size to hand, you can go for a slightly bigger nozzle but ask the advice of an expert first. The smaller the angle, the narrower the fan is. For detailed work, such as removing dirt from a targeted area then a pencil jet (0°) will allow the user to direct all the flow and pressure on a smaller area, increasing cleaning power. Remember, the closer the jet is to the item being cleaned, the more powerful the cleaning performance. A 15 or 25° fan jet is most common. Wide angle nozzles such as 40 upwards tend to be used for spraying rather than cleaning. For example apply a cleaning detergent or chemical. Alternatively, you can use small quick release nozzles, or quick release lances instead.
Sometimes you need the power of a pencil jet but need to cover large areas. Often referred to as turbo nozzles (or dirt killers/dirt blasters), these nozzles consist of a pencil jet that oscillates allowing the user to cover a much larger area, quickly with increased power.
There are other options from different manufacturers that give you all round flexibility, such as the triple nozzle from Karcher; for instance, you can save time cleaning a piece of machinery by first applying detergent using the 40° jet, then using the fan jet for larger areas and the pencil jet for stubborn dirt. This is all done by twisting the nozzle.
There are also nozzles designed specifically for cleaning drains. Drain nozzles often have several orifices: one at the front to power through the blockage, then several facing backwards to help push the nozzle forward and removing/rinsing material missed by the front nozzle. You can also have oscillating rear jets to clean the pipe or drain more effectively.
Finally, there are steam nozzles. Some hot pressure washers have a steam function. Using a higher temperature at a lower pressure suits jobs where high pressure could cause damage. An example might be when cleaning stone.
If your pressure washer performance drops…
Over time, the pressure on the nozzle will cause wear, and the hole will get larger. This will reduce the pressure as the size and spray pattern of the water are changed. Nozzles are usually easy to change – just unscrew the old one and replace it. Some nozzles are on a quick release system.
If you have a question about using pressure washers you can email us: firstname.lastname@example.org or call 0800 888 6662.