How do I calculate / convert GPM to PSI ?

In summary: Assuming a pump around 1 GPH, a 30 gallon drum with holes drilled in one side will need a diameter of around:(0.0005 m^2 x 2 m/s) + (0.0005 m^2 x 0.9 m/s) = 0.0012 mAnd the length will need to be around:(0.0012 m x 0.9 m/s) + (0.0005 m x 2 m/s) = 0.012 m
  • #1
kck
2
0
Ok I should say up front I am not near as brilliant as you fine folks, I was a C student now I am a Dad that can't figure his 11 year olds homework out :yuck:. I hope someone will be so kind as to help me lol.

Scenario:
We are going tuna fishing, so we need a live bait (anchovy) tank. This requires a 30 Gallon plastic rain drum with water flowing in one circular direction to create the needed "current" to make the tuna bait happy. If anchovies are not swimming against current they will die.

I am guessing around 2 MPH in a circular motion. This will be created by a water pump hooked into a pipe that is mounted vertically in the drum with holes drilled in one side on the pipe hence creating the current.

My question: Is there a formula for figuring out the needed GPH pump, vertical pipe size, and size needed for the holes in the pipe?
 
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  • #2
I'm having trouble picturing the tank- presumably water also drains out?

2 miles per hour = 0.9 m/s (more sensible units), and this velocity is basically uniform- if it's the speed of fluid coming out of the hose, and the hose is of reasonable size compared to the tank, you can set up a swirling flow with this speed.

Say you are using a 1" hose: 0.0005 m^2 of area, 1 m/s flow rate = 0.0005 m^3/s volumetric flow = 8 gallons/minute.

That's a rough estimate-YMMV.
 
  • #3
Just like a 50 gallon drum, but smaller 30 gallon. and I am assuming that the holes size drilled pipe matter too?
 
  • #4
kck said:
I am assuming that the holes size drilled pipe matter too?

Again, I am having a hard time picturing what you have in mind.
 
  • #5
Looked for "water flow chart" and found this which might be a start:
http://flexpvc.com/WaterFlowBasedOnPipeSize.shtml

The length, diameter, and resistance of the pipe are important and probably best estimated heuristically. I did some calcs based on our Fire Dept flow charts for different hoses and pumps -- which are way out of your range but might be indicative:
200 feet of hose with a TFT nozzle will run 125 gpm at:
125 psi for 1-3/4" hose
100 psi for 2-1/2" hose
600 feet of 3" supply hose will deliver 125 gpm at about 28 psi
 

1. How do I calculate GPM (gallons per minute) to PSI (pounds per square inch) for a water pump?

To calculate GPM to PSI, you will need to use the following formula: PSI = (GPM x 1715) / (pump efficiency x pump motor efficiency). First, determine the flow rate in GPM. Then, find the pump efficiency and pump motor efficiency, which can be found in the manufacturer's specifications. Finally, plug these values into the formula to calculate PSI.

2. Can I convert GPM to PSI for any type of fluid?

Yes, the formula for converting GPM to PSI can be used for any type of fluid, as long as the pump efficiency and pump motor efficiency are known. However, the specific weight of the fluid may affect the calculation, so it is important to use accurate values.

3. How do I convert GPM to PSI for a fire hose?

To convert GPM to PSI for a fire hose, you will need to know the diameter of the hose, as well as the length and type of nozzle being used. The formula for this calculation is PSI = (0.2 x GPM x (hose diameter)^2) / (nozzle pressure x hose length).

4. Is there a simple way to convert GPM to PSI without using a formula?

There are online calculators and conversion charts available that can easily convert GPM to PSI without the need for a formula. These tools can be useful for quick calculations, but it is always recommended to double check the results using the formula for accuracy.

5. Can I use the same formula to convert PSI to GPM?

No, the formula for converting GPM to PSI is not the same as converting PSI to GPM. To convert PSI to GPM, you will need to use the formula GPM = (PSI x (pump efficiency x pump motor efficiency)) / 1715. This formula uses the same values as the original formula, but rearranges them to solve for GPM instead of PSI.

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