what horsepower is recommended?

[bkel]

Hi all, I am in the process of getting everything ready for my first foray into building my own machine. I am wanting to use a diesel engine (the gas prices are killing me here!) with a 7-8GPM @3600-4000psi. What horsepower diesel would be needed to run such a pump? I currently have an Honda 20Hp pushing my AR 7.92GPM@3600psi, but the 20Hp just doesn't have enough punch in it to do the job.
Any help is much appreciated.

 

[Larry B]

The formula for figuring horsepower required is:
gpm X psi / 1100

8 gpm X 3600 psi= 28800 / 1100 = 26.18 hp required

 

[MR ALAN]

I also run an AR pump with a 20 hp and it does a fine job for me. I prespray just about everything, so max pressure is not needed.
When I do get a larger engine, it will also need to drive the 2000 watt generator that powers the burner. I currently use my larger generator for this as I want max power from the Honda 20 for the AR.

My conversion formula was 8x3600=28800/1450=19.86x1.5= 29.79
I then need an extra 4 hp for the generator. I will get nothing less than a 35 hp

I also use 1/2" pressure hose to achieve more usable pressure. 3/8" hose is a 300 psi loss per 100 feet with 8 gpm vs the 1/2' which is 80 psi per 100.

 

[Dave Olson]

We recently upgraded our White truck. The formula that we used: 10.2 gpm x 3000 psi / 1250 = 24.48 Hp required.

We added an 8000 watt generator (16 Hp required). We installed a 48 Hp Kubota liquid cooled diesel, TSF 2221 General pump, Winco generator.

Been doing a Great job.

Dave Olson

 

[bkel]

thanks for the assistance fellas, i've more of an idea now. I think just to cover myself i will look at a 30Hp engine, which should give me enough power to do what i need to.
We run our machines flat out every day and the 20Hp would stall if pushing the AR too hard, so I had to install a 't' piece tap just after the by-pass to reduce the flow, which meant no more stalls but a slight decrease in pressure and H2O output.
Just a couple of quick questions... how come all three of you have different formulas? and would the output of GPM at the gun be decreased if you reduce to 1/2" hose from 3/8? In most cases for me the GPM is more important than the PSI, but it's nice to have some PSI behind you when you need it!

 

[Larry B]

Not sure why they are different but I believe the 1450 is for electric hp requirements. You could ask Mark the sponsor for more clarification.

 

[Mark]

Pump Education - Troubleshooting
Compliments Of AR North America


HANDY FORMULAS AND CHARTS TO HELP YOU

Q. How can I find the RPM needed to get the specific GPM (Gallons Per Minute) that I want?
A. Needed RPM = Rated RPM x Desired GPM

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Rated GPM

Q. I have to run my motor at a certain RPM. How do I figure the GPM I'll get?
A. Resulting GPM = Rated GPM x Known RPM

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Rated RPM

Q. Is there a simple way to find the approximate horsepower that I'll need to run the pump?
A. Electric Brake HP Required = GPM x PSI

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1450
(Based on 85% overall mechanical efficiency; many pumps are lower.)
Q. What size motor pulley should I use?
A. Pump Pulley O.D. x Motor RPM

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Pump RPM
(O.D. = Outer Diameter) For gas or diesel engine, please consult engine manufacturer.

 

[Mark]

Horsepower Requirements Compliments Of General Pump

Q. How do I calculate the horsepower required for my system?

A. The horsepower required for operation is based on three variables: discharge volume, pressure and drive type. The formula for the calculation is H=(P*G)/C.

Where: H = Horsepower

P = Pressure in PSI

G = Flow in GPM

C = Drive constant:

Hydraulic C = 1714

Electric C = 1460

Gasoline C = 1250 (Industrial grade)

Gasoline C = 1100 (Standard grade)

Diesel C = Supplied by Engine Mfr.

This will give you an estimate of the horsepower required for the system. To specifically determine required horsepower, motor and drive efficiencies must be considered. Contact your motor supplier for these values.

 

[MR ALAN]

would the output of GPM at the gun be decreased if you reduce to 1/2" hose from 3/8?

!/2" hose is larger than 3/8", so it would allow the machine to work better.

 

[TRAVISJ]

hydraulic drive

Has Any One Built A Truck Setup That Used A Pto From The Truck To Drive Aydraulic Motors To Run There Pumps. I Was Thinking Of Buliding A Setup With Two Pumps Would This Work. With Fuel Prices And Engine Maint Only One Engine To Run Truck, And Pumps Would Be Efficient. Yea Or Nay!!!!!!

Oh Yea Diesel Only.

 

[grasshawg]

Travis, check with Eric Fisher, aka "north coast". I seem to recall him posting something to that effect. He'll probably reply to your post shortly.
Randy

 

[north coast]

Travis,

Check out our web site for some more info on our PTO set up www.jwsservicesystems.com They have great advantages over running separate skid mounted machines. Our trucks still average 4.8 - 6.5 gpm and that includes them running while washing, driving, and supplying fuel for the burners. Plus you can keep the A/C running on those hot days and the heat on the cold days. We can run 3 pumps at the same time or you can mount other equipment to them like generators, vac pumps, blowers for duct cleaning etc. Use an electric clutch to turn things on and off with the flick of a switch.