Michael
New member
Be aware that these are guides and not hard and fast rules. Sorry about some of the math but most calculators will handle it 
?
Horsepower required: Flow (GPM) x Pressure (PSI) / 1460 = Electric Motor HP
Electric motor Horsepower x 1.5 = Gasoline Engine HP
Using the above formula and substituting 1100 for the 1460 arrives at an answer used by some manufacturers for Gasoline Engine HP. This is an 'Engineering Theoretical Performance' value derived from all components working perfectly according to theory. I do not find this to be realistic.
Using the above formula you can derive the following unknown values if you know part of the information.
Flow (GPM) = (HP / Pressure) x 1460
Pressure (PSI) = (HP / Flow) x 1460
For the correct nozzle size use the following:
Nozzle # = GPM x [Square root of (4000 / PSI)] A #4 nozzle will give you 4 GPM at 4000 PSI.
Therefore, GPM = Nozzle # x [Square root of (PSI / 4000)] and
PSI = (GPM / Nozzle #) Squared x 4000
On average you will lose 24 PSI per 100' run of 1/2" ID hose at 4 GPM; 34 PSI @ 5 GPM and 52 PSI at 6 GPM.
NEVER fall for Cleaning Units or Cleaning Performance numbers derived from GPM x PSI. This is not an accurate formula for comparison; this however is:
Reaction Force (in Pounds) = [GPM x (Square root of PSI)] / 18.92.
Therefore using a 2 GPM @ 1000 PSI unit as the start;
RF is (2 x 31.62) / 18.92 = 3.34#.
Double the flow to 4 GPM (4 x 31.62) / 18.92 = 6.69#.
Double the pressure but keep the flow (2 x 44.72) / 18.92 = 4.73#
Quadruple the pressure but keep the flow (2 x 63.25) / 18.92 = 6.69#
As I have said before FLOW IS OF MORE VALUE THAN PRESSURE, now you know why.
100,000 BTU will give a 140 degree F (60 C) heat rise per gallon of water. This is a Rule of Thumb as efficiencies of coils vary from manufacturer to manufacturer.
Forgot about water; it weighs 1 kilogram/ litre or 10 pounds/ Imperial gallon or 8.35 pounds/ US gallon.
The above information must be credited to Cat Pumps, Giant Pumps, Beckett Burners and my science teachers.
Hope this helps? Cheers.
?Horsepower required: Flow (GPM) x Pressure (PSI) / 1460 = Electric Motor HP
Electric motor Horsepower x 1.5 = Gasoline Engine HP
Using the above formula and substituting 1100 for the 1460 arrives at an answer used by some manufacturers for Gasoline Engine HP. This is an 'Engineering Theoretical Performance' value derived from all components working perfectly according to theory. I do not find this to be realistic.
Using the above formula you can derive the following unknown values if you know part of the information.
Flow (GPM) = (HP / Pressure) x 1460
Pressure (PSI) = (HP / Flow) x 1460
For the correct nozzle size use the following:
Nozzle # = GPM x [Square root of (4000 / PSI)] A #4 nozzle will give you 4 GPM at 4000 PSI.
Therefore, GPM = Nozzle # x [Square root of (PSI / 4000)] and
PSI = (GPM / Nozzle #) Squared x 4000
On average you will lose 24 PSI per 100' run of 1/2" ID hose at 4 GPM; 34 PSI @ 5 GPM and 52 PSI at 6 GPM.
NEVER fall for Cleaning Units or Cleaning Performance numbers derived from GPM x PSI. This is not an accurate formula for comparison; this however is:
Reaction Force (in Pounds) = [GPM x (Square root of PSI)] / 18.92.
Therefore using a 2 GPM @ 1000 PSI unit as the start;
RF is (2 x 31.62) / 18.92 = 3.34#.
Double the flow to 4 GPM (4 x 31.62) / 18.92 = 6.69#.
Double the pressure but keep the flow (2 x 44.72) / 18.92 = 4.73#
Quadruple the pressure but keep the flow (2 x 63.25) / 18.92 = 6.69#
As I have said before FLOW IS OF MORE VALUE THAN PRESSURE, now you know why.
100,000 BTU will give a 140 degree F (60 C) heat rise per gallon of water. This is a Rule of Thumb as efficiencies of coils vary from manufacturer to manufacturer.
Forgot about water; it weighs 1 kilogram/ litre or 10 pounds/ Imperial gallon or 8.35 pounds/ US gallon.
The above information must be credited to Cat Pumps, Giant Pumps, Beckett Burners and my science teachers.
Hope this helps? Cheers.
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