What is the Importance of Pressure and Flow Rate in Pressure Washers?

Understanding the Importance of Pressure and Flow in Pressure Washers

Every component of a pressure washer must be able to handle pressurized water, often at different temperature settings. Understanding pressure and flow rate in pressure washers can help you recognize potential points of failure and choose the right pressure washer solutions and replacement parts. Follow these pressure water tips to select the ideal pressure washer system for your application.

Understanding Pressure and Flow Rate in Pressure Washers

Both cold- and hot-water pressure washers can be described in terms of pressure in pounds per square inch (PSI) and flow rate in gallons per minute (GPM). The pressure rating measures the water’s force and ability to dislodge grime, dirt, and deposits. A higher pressure rating means the washer can clean hard-to-remove deposits. The flow rate measures the volume of water released from the washer during operation. A higher flow rate means the washer can remove deposits from a surface faster than a washer with a lower flow rate.

Flow and pressure are complementary ratings that determine the cleaning power of a pressure washer. As a general rule of thumb, higher flows and higher pressure levels provide better cleaning power because the water stream can quickly and effectively dislodge stuck-on grime, organic debris, deposits, and even old paint. However, it’s not always best to use the highest possible pressure or flow rate; lower flow rates are typically best for smaller objects and higher flow rates are best for large objects.

For best results, use a pressure washer with an optimal pressure and flow rating. A high-pressure, low-flow washer will not provide the full benefits of having high pressure. Similarly, a high-flow, low-pressure washer will not provide the full benefits of having a high flow rate. For these reasons, optimal pressure washer performance is typically grouped as combinations of certain flow rates and pressures. These are the most common flow and pressure ratings for pressure washers:

2.2 GPM at 1000 PSI
3 GPM at 1500 PSI
4 GPM at 2000 or 2500 PSI
4 GPM at 4000 PSI
5 GPM at 3000 PSI
5 GPM at 5000 PSI

Importance of Pressure and Flow Rate in Pressure Washers

Once you understand the relationship between pressure and flow, you can strategically apply that knowledge to the items you need to clean. Simply using the highest possible pressure level will not get the job done faster and can even cause damage. Every combination of surface and contaminant has a specific pressure and flow rate that will separate the two.

For example, cleaning grease from stainless steel requires a different pressure than cleaning grease from cast iron or aluminum. Removing paint, tar, or chewing gum from a stainless steel surface also requires different pressure levels. Using a pressure washer with the optimal pressure and flow rate combination will help you complete the task effectively in the least amount of time.

Ultimately, pressure rating is only valuable up to a point. Once you’ve reached the highest recommended pressure level for a given scenario, the flow rate should then be increased to speed up the task. In fact, flow rate is crucial to determining the amount of time a cleaning task will take. To find out how one pressure washing system will work compared to others, multiply the pressure at which a given system operates by its flow rate in gallons per minute. This comparison should help you select the best pressure washer for your application.

Get High-Pressure Cleaning Systems From Spartan Manufacturing

Now that you have a better understanding of how to use pressure washers according to their pressure and flow ratings, you’re ready to choose a pressure washer for your project. At Spartan Manufacturing, we provide quality high-pressure washers and replacement parts. We guarantee the availability of replacement components for at least 10 years from the date of manufacture. All products are supported by our exceptional customer support and service technicians, and we can help you select the ideal pressure washer for your unique needs.