A pressure washer earns its place on a farm quickly. Caked soil on implements, residue in dairy sheds, chemical build-up on a sprayer, machinery being prepared for service — all of it is faster and more thorough with pressure than with a brush and bucket.
The two numbers on the label matter in different ways, and most buyers only look at one of them.
Pressure and flow are not the same thing
Pressure is the force at the nozzle. It breaks the bond between dirt and surface. Higher pressure cuts through baked-on soil, but it is also what damages paint, seals and soft surfaces if misused.
Flow rate is the volume of water per minute. It carries the loosened dirt away. This is the number people ignore, and it is why a high-pressure machine with low flow can feel slower on a big dirty surface than a moderate machine with good flow.
For farm cleaning, both matter: pressure to break the bond, flow to rinse it off. On large muddy surfaces, flow does more of the work than people expect.
Nozzles change everything
Most machines come with several nozzles or an adjustable tip, defined by spray angle:
- Zero degrees (pencil jet) — all the force in one point. Useful for a single stubborn spot on hard metal. It will strip paint and cut soft material, and it can injure skin. Use it rarely and never on a person, an animal or a tyre.
- Fifteen degrees — heavy-duty stripping on hard surfaces such as concrete and steel implements.
- Twenty-five degrees — the general-purpose choice for machinery and vehicles.
- Forty degrees — wide, gentle. For paintwork, rinsing and delicate surfaces.
- Soap nozzle (low pressure) — for applying detergent before the pressure pass.
Start with the widest nozzle and work narrower only if you need to. Start far from the surface and move closer. It is very easy to take paint off a tractor bonnet and impossible to put it back.
Cleaning farm machinery without causing damage
- Never aim directly at bearings, seals or the gearbox breather. High-pressure water forces past seals and washes grease out, and the damage shows up weeks later as a failed bearing.
- Keep away from electrical connectors, the alternator and the air intake.
- Do not aim at decals, radiator fins or hydraulic hoses at close range.
- Re-grease nipples and pivot points after washing. You have almost certainly removed some grease.
- Dry and oil bare metal on implements to prevent flash rust.
Cleaning a sprayer
This is one of the best uses on a farm. Chemical residue on the outside of a sprayer is a contamination and corrosion risk. Wash the outside with a wide nozzle at moderate pressure, and flush the inside with clean water through the pump and lines as normal — never use the pressure washer to force water backwards through a sprayer pump.
Collect and dispose of the runoff responsibly, away from wells, canals and drains.
Practical operating points
- Water supply matters. Starving a pressure washer of water damages the pump faster than anything else. Check the inlet filter and make sure the supply keeps up with the machine's flow rate.
- Never run it dry, even briefly.
- Release the trigger periodically rather than holding the gun closed for long periods on machines without an auto stop.
- Drain the pump before storage.
- Wear eye protection and boots. Debris comes back at you, and a close-range jet will injure skin.
Choosing a machine
For light vehicle and equipment washing, a compact machine is adequate and easier to store. For daily use on heavily soiled implements, dairy sheds or hard floors, buy for flow as well as pressure and for a duty cycle that suits continuous work.
See the pressure washer and car washer range and the spray guns and high-pressure nozzles, or tell us what you clean most often and how often.