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HOW TO: High Pressure Nozzle Selection & Sizing

August 8, 2017

By: Hydra-Flex, Inc.

As featured in Kleen-Rite’s Kleen-Scene Magazine | August 2018

Various nozzle styles are available for different types of car wash applications.  Just like picking the right tool from your toolbox – do you need a screwdriver, a hammer, or a wrench?  When selecting nozzles, it’s important to understand the type of application it’ll be used in, the quantity and size of nozzles your pump(s) can support, and if there are any important regulatory or water saving considerations.


Wheels, Rockers, Undercarriage, and Other Blasting Car Wash Applications:

For high-pressure cleaning and blasting applications, we recommend using a rotating or “turbo” nozzle.  These types of nozzles blast a 0-degree stream while rotating at an optimized speed to form a cone-shaped spray pattern.  The high-impact, pencil-jet style stream blasts away dirt using very little water while the cone-shape covers the vehicle like a flat-fan nozzle.

FEATURED PRODUCT: Blast-Tec Pro™ Rotating Turbo Nozzle

Blast Tec Pro

What customers are saying –Includes a corrosion resistant stainless steel housing and precision-machined tungsten carbide nozzle tips and seats for long life and smooth operation. Greater impingement allows you to use a smaller Blast-Tec Pro nozzle size while getting the same impact as nozzles with higher GPM flow rates.

“…the improvement was both immediate and dramatic. Wash quality improved out of sight. The rotating strobe spray pattern of the Hydra-Flex nozzle improved the coverage over the vehicle surface considerably.” –Richard Davison, Shiners Car Wash Systems

Pivoting, Oscillating, or Spinning Car Wash Applications

For pivoting, oscillating, or spinning high-pressure vehicle wash applications, we recommend using a zero-degree, solid-stream nozzle due to their high quality streams that stay intact over long distances. These types of nozzles use a concentrated, high-impact 0-degree water jet that attacks tough road grime and easily moves and rinses soap from the vehicle.

FEATURED PRODUCT: Blast-Force™ Static, 0° Solid Stream Nozzle

Blast ForceWhat customers are saying –Blast-Force™ is a zero-degree, solid-stream nozzle with superior wear and corrosion-resistance of tungsten carbide nozzle orifices, and is ideal use for reclaim water. Greater impingement allows you to use smaller nozzle sizes with lower GPM flow rates without sacrificing cleaning results.

“Now that we have installed the Blast-Force and Blast-Tec Pro nozzles, our cost of water is about $0.30 per car. Our initial reason for switching to Hydra-Flex nozzles was to save water, and we have already experienced over 30% savings.” –Dan Crader, Best Express Car Wash

Pressure Washing and Industrial Cleaning Applications

For industrial cleaning applications – such as pit cleaning, wall cleaning, and any other off-site pressure washing needs – rotating turbo nozzles which operate at higher pressures (ranging from 1500 to 7500 PSI) are recommended for optimal cleaning results. These nozzles blast a concentrated, high-impact 0-degree water jet while rotating at a high speed to form a cone-shaped spray pattern.

FEATURED PRODUCT: Aqua-Rocket™ Industrial Turbo Nozzle

Aqua RocketWhat customers are saying –Equipped with a drop-resistant, high-temperature rubber cover, these heavy-duty nozzles are constructed with stainless steel housings and tungsten carbide nozzle tips/seats to withstand harsh environments and provide longer life than ceramic nozzles. The Aqua-Rocket’s optimized stream quality results in greater impingement, allowing your to easily attack tough dirt and grime. In lab tests, on average, the Aqua-Rocket™ applied 95.18% greater impingement force than competitors.

“After testing and switching to the Aqua-Rocket, this [cleaning] process’s overall completion time dropped by more than 50%. I can’t speak for everyone, but in our industry this is huge because it enables us to repurpose more than 8 employee man hours for other tasks – resulting in finishing cleanups faster and more efficiently!” –Chadwick Kogelschatz, Roskam Baking Company


Matching Nozzles to Pump

Proper nozzle selection should take into consideration the type of application, your pressure setting, distance from the substrate, and the nozzle number size.

Your pump must be capable of producing the proper amount of PSI needed for the total GPM flow rate of all the nozzles required for the application. For instance, a #4.0 nozzle will always do 2.0 GPM at 1000 PSI. See the below flow rate chart to match your nozzle size to your pump.



Over sizing your nozzle to your pump capacity could result in:

  • Low Flow/Pressure – can cause improper nozzle functionality, such as low operating pressure, poor rotation, and low impingement/cleaning power.

Under sizing your nozzle to your pump capacity may result in:

  • High Flow/Pressure – over pressurized streams may cause damage to the substrate.
  • Bypassing Water – can cause water to heat up, ultimately leading to system damage to due high temperatures.