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What is the Difference between Plunger Pumps and Piston Pumps?
What is the difference between plunger pumps and piston pumps for pressure washing? What are the similarities? Which is better? A complete guide to plunger pumps vs. piston pumps explained.
Choosing the Right Pump for Your Pressure Washer
The type of pump you choose can make all the difference when it comes to pressure washing. Whether you're tackling high-pressure applications like blasting oil off concrete or lower-pressure tasks like washing your car, understanding the differences between plunger pumps and piston pumps is crucial.
Similarities Between Piston & Plunger Pumps
Before we dive into the differences, let's look at what piston and plunger pumps have in common:
- Both are reciprocating positive displacement pumps
- They pull water through an intake valve into a chamber
- They push pressurized water out through an outflow valve
- Most are either duplex (two pistons/plungers) or triplex (three pistons/plungers) variants
Triplex pumps are generally preferred as they last longer and provide a more constant water flow, reducing strain on components.
How Pumps Work and Common Applications
Plunger Pumps
Plunger pumps are designed for high-pressure applications and use a durable reciprocating ceramic plunger. The high-pressure seal remains stationary, allowing plunger pumps to handle much higher pressures than piston pumps.
Common Applications for Plunger Pumps:
- Industrial Cleaning: Ideal for heavy-duty tasks like removing grease from machinery.
- Graffiti Removal: Effective at blasting away tough stains from concrete or brick surfaces.
- Concrete Surface Cleaning: Perfect for cleaning driveways and sidewalks where high pressure is needed.
Piston Pumps
Piston pumps offer versatility for a range of cleaning tasks. They use reciprocating pistons similar to plunger pumps, but the high-pressure seal is attached and moves with the piston. This design means piston pump seals wear out faster and generally can't handle as much pressure as plunger pumps.
Common Applications for Piston Pumps:
- Residential Use: Great for washing cars, patios and siding.
- Light Commercial Cleaning: Suitable for smaller businesses needing regular maintenance without heavy-duty demands.
- Soft Washing Applications: Effective in low-pressure situations, such as cleaning roofs without damaging shingles.
Diagnosing Pressure Washer Problems
It's important to note pump failure is rarely the root cause of pressure washer issues. Common problems include:
- System restrictions (leading cause): Blockages in the pressure washer's plumbing create excessive strain on the pump by preventing proper fluid flow and increasing internal pressure.
- Cavitation due to insufficient water supply: Inadequate water volume creates vapor bubbles that damage pump components and reduce system efficiency.
- Damaged pistons or plungers: Wear or cracks compromise the pump's ability to generate consistent pressure and fluid movement.
- Worn packings: Deteriorated seals cause fluid leaks and reduced pressure, preventing proper pump performance.
- Abrasive materials in the pumped fluid: Particulates cause rapid wear on internal pump surfaces, leading to premature component failure.
- Excessively high liquid temperatures: Overheating degrades seals, breaks down fluid and can warp critical pump components.
- Broken crankshafts: A fractured crankshaft stops the pump's mechanical motion, leaving the pressure washer inoperable.
Regular maintenance is necessary to keep your pressure washer pump working as long as its hourly rating suggests.
Maintenance Tips for Each Pump Type
Proper maintenance can significantly extend the life of your pressure washer pump. Here are some tips tailored to each type:
Caring For Plunger Pumps:
- Inspect Seals Regularly: Check the high-pressure seals for wear and replace them as needed.
- Clean Filters Frequently: Make sure inlet filters are free from debris to prevent cavitation.
- Flush After Use: Run clean water through the system after each use to remove any residual detergents or debris.
Caring For Piston Pumps:
- Monitor Seal Condition: Since seals wear out faster, inspect them regularly and replace them if you notice leaks or reduced pressure.
- Keep It Cool: Avoid running the pump with excessively hot water, which can damage seals.
- Use Appropriate Detergents: Make sure any detergents used are compatible with your pump type to avoid damaging seals.
Choosing the Right Pump for Your Needs
When deciding between a plunger pump and a piston pump, consider:
- The intensity of your cleaning tasks
- Frequency of use
- Budget (plunger pumps are often more expensive but more durable)
- Maintenance requirements
For high-pressure, frequent use, a plunger pump might be your best bet. For occasional, lighter use, a piston pump could be sufficient.
Need Help? Contact the Power Wash Store
Choosing the right pump for your pressure washer can be challenging. If you're stuck or have questions, don't hesitate to reach out. Our expert team at The Power Wash Store is ready to help you find the perfect solution for your cleaning needs.