Tip Sizes on Nozzles

Both the size of the spray nozzle orifice or outlet and its shape affect the amount and type of cleaning work water directed through the nozzle will be able to accomplish. Orifice diameter (the diameter of the hole in the discharge side of the nozzle) determines the pressure produced at a particular flow. A smaller orifice will produce a higher pressure or psi figure at a specific flow or gpm than a larger orifice.

The shape of the nozzle outlet determines the spray pattern, which is generally either straight stream or fan spray. The more concentrated or narrower the spray pattern, the less surface will be covered but with more impact of water against the surface. Fan jet patterns are offered in 15°, 25° and 40°.

The Difference Size Makes
To see the difference orifice diameter makes in flow and pressure, compare a 6.5 and a 4.0 spray nozzle. At a flow of 2 gpm:
  • The 6.5 spray nozzle produces pressure at about 400 psi.
  • The 4.0 spray nozzle, produces 1000 psi at the same flow.

  • The higher the flow and pressure, the greater the impact and cleaning power. The narrower the Fan degree, the height the impact on the surface.

    Sizing Spray Nozzles
    Spray nozzles are sized to produce the equipment's rated flow and pressure. Spray nozzle sizing for most pressure and flow ratings are included in the spray nozzle chart. This chart is easy to read Look at the top of the chart where there are captions for columns representing pressures from 25 to 7000 psi. Spray nozzle sizes are assigned to each line. The flow rate produced by that spray nozzle size at the psi is entered in each column on a line.

    To find the correct spray nozzle size, look up the psi rating of the machine in the line of captions at the top of the page. Run your finger down the column till you get to the closest entry to the GPM flow produced by the machine.

    If you do not have the exact size when selecting spray nozzle, use the next size larger rather than a smaller because moving water through the smaller orifice will require more effort from the pump and also will start to release the unloader.

    Spray nozzles for cleaning range are available at 0 degrees (stream) 15°, 25° and 40° spray pattern spreads. The narrower the stream of water coming out of the nozzle, the more impact, but the less coverage and the longer it might take to clean a specific area.

    The most popular nozzle is the 25° nozzle, which is considered to represent the best compromise between spray pattern coverage and impact. Using a 15° nozzle trades off greater impact for less coverage this is useful for small spot cleaning like gum and oil or paint droplets. The widest-angle nozzles 40° to 65°are for Rinsing or Detergent application.

    See Chart Below
    Detail