Phone: 800-231-3134

There are two considerations for choosing the right nozzle for your pressure washer:

  1. The type of nozzle
  2. The orifice of the nozzle

The type of nozzle is all about efficiency – you will be able to cut down on cleaning time by using a different type of nozzle.

There are standard nozzles with different spray angles and there are rotary nozzles (or turbo nozzles) that spray in a circular pattern and cover more area, which will reduce your cleaning time.

The article is about the orifice of the nozzle.

The orifice is the “hole” in the nozzle that allows the water to pass through the nozzle itself. There are different size orifices (or holes) that range from 2 to 60 - a “number 2” orifice is smaller than a “number 8.5” orifice.

Each pressure washer should have a specific nozzle size that comes with it.

To better explain the importance of the orifice, I will use an example where a garden hose is used to water a yard.

Imagine that you have a 10ft. hose and you need to water a yard that is 20 feet deep. To reach the far end of the yard you will have to constrict the water flow by placing your thumb on the hose and forcing the water to through a smaller opening. This will make the water stream faster out of the hose.

Now image that someone opens the spigot to let more water flow. Two things happen:

  1. The water will squirt deeper into the yard AND
  2. More back pressure will be placed on the spigot

To relieve the additional pressure you will have to ease the pressure off the hose, allowing more water to flow, this will also reduce the distance the water reaches into the yard.

The example we just gave deals with garden hose pressures of about 40 pounds per square inch (PSI), on a pressure washer, PSI ranges from 1,000 to over 4,000.

If your pressure washer has water flow of 2.5 Gallons per Minute and a PSI rating of 2,000, imagine what might happen if you restrict the flow by using a nozzle with a smaller hole.

Using a smaller orifice will cause an increase in pressure, which will cause pump failure and may cause injury to the operator.

The table below shows the correct orifice based on your pressure washer’s specifications.

  1. Find the PSI in top column
  2. Move down the column until you find the GPM
  3. The orifice size will be the number in the left column of the table

For example:

If your pressure washer’s PSI is 1,750 and the GPM is 3.31, then the correct orifice number is “5”

For more information on nozzles and other accessories to speed up your cleaning contact Williams Cleaning Systems at 800-231-3134.

 

Nozzle Size Pounds Per Square Inch (PSI)
  500 750 1000 1250 1500 1750 2000 2250 2500 2750 3000 3250 3500 3750 4000 4500 5000
2 0.71 0.87 1.00 1.12 1.22 1.32 1.41 1.50 1.58 1.66 1.73 1.80 1.87 1.94 2.00 2.12 2.24
2.5 0.88 1.08 1.25 1.40 1.53 1.65 1.77 1.88 1.98 2.07 2.17 2.25 2.34 2.42 2.50 2.65 2.80
3 1.06 1.30 1.50 1.68 1.84 1.98 2.12 2.25 2.37 2.49 2.60 2.70 2.81 2.90 3.00 3.18 3.35
3.5 1.24 1.52 1.75 1.96 2.14 2.32 2.47 2.63 2.77 2.90 3.04 3.15 3.27 3.39 3.50 3.71 3.91
4 1.41 1.73 2.00 2.24 2.45 2.65 2.83 3.00 3.16 3.32 3.46 3.61 3.74 3.87 4.00 4.24 4.47
4.5 1.59 1.95 2.25 2.52 2.76 2.98 3.18 3.38 3.56 3.73 3.90 4.06 4.21 4.36 4.50 4.77 5.03
5 1.77 2.17 2.50 2.80 3.06 3.31 3.54 3.75 3.95 4.15 4.33 4.51 4.68 4.84 5.00 5.30 5.59
5.5 1.94 2.38 2.75 3.07 3.37 3.64 3.89 4.13 4.35 4.56 4.76 4.96 5.14 5.33 5.50 5.83 6.15
6 2.12 2.60 3.00 3.35 3.67 3.97 4.24 4.50 4.74 4.97 5.20 5.41 5.61 5.81 6.00 6.36 6.71
6.5 2.30 2.81 3.25 3.63 3.98 4.30 4.60 4.88 5.14 5.39 5.63 5.86 6.08 6.29 6.50 6.89 7.27
7 2.47 3.03 3.50 3.91 4.29 4.63 4.95 5.25 5.53 5.80 6.06 6.31 6.55 6.78 7.00 7.42 7.83
7.5 2.65 3.25 3.75 4.19 4.59 4.96 5.30 5.63 5.93 6.22 6.50 6.76 7.02 7.26 7.50 7.95 8.39
8 2.83 3.46 4.00 4.47 4.90 5.29 5.66 6.00 6.32 6.63 6.93 7.21 7.48 7.75 8.00 8.49 8.94
8.5 3.01 3.68 4.25 4.75 5.21 5.62 6.01 6.38 6.72 7.05 7.36 7.66 7.95 8.23 8.50 9.02 9.50
9 3.18 3.90 4.50 5.03 5.51 5.95 6.36 6.75 7.12 7.46 7.79 8.11 8.42 8.71 9.00 9.55 10.06
9.5 3.36 4.11 4.75 5.31 5.82 6.28 6.72 7.13 7.51 7.88 8.23 8.56 8.89 9.20 9.50 10.08 10.62
10 3.54 4.33 5.00 5.59 6.12 6.61 7.07 7.50 7.91 8.29 8.66 9.01 9.35 9.68 10.00 10.61 11.18
11 3.89 4.76 5.50 6.15 6.74 7.28 7.78 8.25 8.70 9.12 9.53 9.92 10.29 10.65 11.00 11.67 12.30
12 4.24 5.20 6.00 6.71 7.35 7.94 8.49 9.00 9.49 9.95 10.39 10.82 11.22 11.62 12.00 12.73 13.42
12.5 4.42 5.41 6.25 6.99 7.65 8.27 8.84 9.38 9.88 10.36 10.83 11.27 11.69 12.10 12.50 13.26 13.98
13 4.60 5.63 6.50 7.27 7.96 8.60 9.19 9.75 10.28 10.78 11.26 11.72 12.16 12.59 13.00 13.79 14.53
15 5.30 6.50 7.50 8.39 9.19 9.92 10.61 11.25 11.86 12.44 12.99 13.52 14.03 14.52 15.00 15.91 16.77
20 7.07 8.66 10.00 11.18 12.25 13.23 14.14 15.00 15.81 16.58 17.32 18.03 18.71 19.36 20.00 21.21 22.36
25 8.84 10.83 12.50 13.98 15.31 16.54 17.68 18.75 19.76 20.73 21.65 22.53 23.39 24.21 25.00 26.52 27.95
30 10.61 12.99 15.00 16.77 18.37 19.84 21.21 22.50 23.72 24.87 25.98 27.04 28.06 29.05 30.00 31.82 33.54
40 14.14 17.32 20.00 22.36 24.49 26.46 28.28 30.00 31.62 33.17 34.64 36.06 37.42 38.73 40.00 42.43 44.72
50 17.68 21.65 25.00 27.95 30.62 33.07 35.36 37.50 39.53 41.46 43.30 45.07 46.77 48.41 50.00 53.03 55.90
60 21.21 25.98 30.00 33.54 36.74 39.69 42.43 45.00 47.43 49.75 51.96 54.08 56.12 58.09 60.00 63.64 67.08