This article explains how pressure is generated in a SPITWATER pressure cleaner. While it may seem like the machine is simply “pushing water,” the system behind the scenes is a carefully calibrated combination of pump action, pressure restriction and nozzle design.
Understanding this process can help you operate your cleaner more effectively, troubleshoot performance issues and avoid damaging components.
How Pressure is Created
At the heart of every SPITWATER pressure cleaner is the pump. It works like a motorised groundwater hand pump, only instead of using your arm, the pump is powered by a high-speed electric motor or a Honda petrol engine, depending on your machine type.
As the pump moves back and forth:
- It draws water in through the inlet valve on one stroke
- Then pushes water out through the outlet valve on the return stroke
This high-speed back-and-forth movement moves water through your high-pressure hose.
The Role of the Hose and Trigger Gun
Water leaves the pump and travels through a wire mesh-reinforced hose, designed to withstand high pressure without swelling or bursting.
At the end of the hose is your gun, fitted with a trigger. Pulling the trigger opens the valve, allowing water to move forward through to the nozzle.
Pressure Happens at the Nozzle
This is where the magic happens.
The nozzle creates the restriction that builds pressure. Without it, the water would simply flow out at low pressure, just like removing a hose from the machine and turning it on. You’d see flow, but not cleaning force.
Each SPITWATER machine is matched with a precisely sized nozzle, featuring a small opening engineered to restrict water flow in just the right way. This restriction builds the high pressure that blasts away grime, dirt and grease.
Common Pressure Problems and Causes
|
Symptom |
Likely Cause |
Check/Fix |
|
Low or no pressure at the gun |
Missing or incorrect nozzle |
Ensure correct nozzle size and type is fitted; replace worn nozzles |
|
Nozzle is blocked or damaged |
Remove nozzle and inspect; clean or replace as needed |
|
|
Leaking trigger gun |
Inspect trigger for drips; replace seals or gun if leaking |
|
|
Inlet water supply is restricted or insufficient |
Check hose for kinks or obstructions; ensure full flow from tap |
|
|
Air in the system |
Bleed system by running machine with trigger open until steady flow returns |
|
|
Pulsing pressure |
Trigger gun leaking or not fully sealing |
Check for wear or damage inside gun; replace if needed |
|
Debris in pump valves or worn seals |
Service pump valve kit and inspect for dirt or wear |
|
|
Good flow but low cleaning power |
Worn nozzle (too large an opening) |
Replace nozzle with correct spec for your machine |
|
Wrong nozzle fitted |
Cross-check nozzle size and machine specs |
|
|
Pressure drops after trigger released |
Blocked unloader or bypass valve issue |
Service the unloader/bypass valve—inspect for blockages or spring issues |
|
Machine not shutting down properly due to leaking gun |
Replace leaking trigger gun to allow proper shut-off and pressure reset |
Why It Matters
If you’re experiencing pressure issues, don’t just look at the pump. A worn or incorrect nozzle, kinked hose or leaking trigger can all disrupt the pressure system.
Understanding how pressure is generated helps you:
- Operate your cleaner more effectively
- Diagnose loss of pressure
- Maintain machine performance over time
⚠️ Safety Reminder
Never run the machine without the correct nozzle installed. Doing so may cause low pressure operation and risk damaging the pump.
If unsure, consult a qualified SPITWATER service technician.
Want to Clean Smarter, Not Harder?
Choosing the right machine isn’t about buying the biggest or most expensive model. It’s about matching the machine to your job, your workflow and your crew.
All SPITWATER industrial pressure cleaners are:
- Made in Australia for Australian conditions
- Engineered with serviceability and durability in mind
- Supported by a national network of dealers and spare parts
- Customisable with a wide range of accessories, chemicals and setups
Need help choosing?
Watch the full video or speak with one of our specialists to build a setup that works as hard as you do.
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