Tip size impact

[soapy]

We get a lot of questions on what tip size to use. I found the formula for converting the flow rate and pressure to Foot lbs. Once you have the foot lbs. for flow rate and pressure the only variable is the spread pattern of the tip. For example a 15 degree tip would have 3 times the impact of a 45 degree tip with the same flow rate. So here are the foot lbs. rating for .05-.08 (2.5gpm-4.0 gpm) at 1000 psi. .05 =4.16 .06=5.0 .07=5.82 .08=6.65 At 1500 psi .05=5.09 .06=6.11 .07=7.13 .08=8.14

 

[Greg]

Thank you Soapy for sharing data, it is helpful reference !
I formatted your information to column form, and added 1200 PSI measurements and GPM flow.

Please check for discrepancies as I could not find the formula.

Foot lbs. rating for #05 - #08 nozzles (GPM flow through the nozzle is shown in parenthesis)

Nozzle#_______1000 psi______1200 psi______1500 psi
#05__________4.16 (2.5)_____4.56 (2.74)____5.09 (3.06)
#06__________5.0 (3.0)______5.47 (3.29)____6.11 (3.67)
#07__________5.82 (3.5)_____6.37 (3.83)____7.13 (4.29)
#08__________6.65 (4.0)_____7.29 (4.38)____7.99 (4.8)

Greg Thoennes
Arimitsu Pumps

 

[soapy]

The formula I found was in a catalog of Spray Systems. K x gpm @ pressure x ( square root of the psi used). K is equal to constant which for water ft. lbs is .0526 gpm ( gallons per minute at pressure) square root of 1000 = 31.62, SRof 1500 is 38.73 , SR of 1200 is 34.64 I looked at the formula again ( it is found in catalog 75 page A9 ). I discovered I should have used the actual gallons per minute at flow rate of pressure used. Initially I used flow rate at 1000 psi. This means all the numbers for 1000 psi are correct but not for the others. Here are the corrected numbers using Gregs gpm per pressure.

Nozzle------------- 1000psi -------1200 psi--------- 1500 psi
#05 ------------- 4.16 -----------4.57-------------5.09
#06 ------------- -5.0 -------------5.58-------------7.47
#07 ------------- 5.82-------------6.98------------ 8.74
#08 ------------ 6.65 -------------7.98------------9.78

 

[mac]

What is left unsaid is how does the impact vary with distance. It varies by following what is called the inverse square law. (Now how many times can you work that into a conversation?) That means that if you double the distance from the tip to the surface, the measured impact will be 1/4 of the first. It is one reason I get a chuckle when I see any operator with an inverted L machine bragging about their machine. You know who you are. The horizontal part of the wand is usually about four feet away from the hood and trunk of a car. So is you have 1000 psi at the tip, the real impact pressure there is 1/16 of that, or around 60 psi. Please correct me if my math ain't right.

 

[soapy]

Mac, I think you are generally correct about distance factor. A variable would be the amount of water being used. A higher amount of water would retain more of its impact vs. a lower water amount at any given pressure.