[dvldoc]

I have not updated this since about a year and a half when we use to use 100psi pumps which are different from the new custom ones we have now, Kinda forgot to check to see the differences.

Well here is what I got.

Test conducted with a snubbed 3" Glycerin-Filled Gauge with NIST Certificate. Keeps things nice and smooth with no guessing on accuarcy.

12-30VDC Power supply at 13.25 volts. All numbers rounded down to the nearest multiple of 5.

M2 230psi
M3 225psi
M4 215psi
M5 190psi
M7 180psi
M10 170psi
M12 Not tested (didnt have one handy here on Guam)
M14 155 psi

A pretty big jump in numbers over the old pump due to the change in the cams and other minor changes.

You really don't want a excessive amount of pressure do to additional stress on the seals and internals of the pump. The number were a bit higher than I expected with the M3 and M2.

[Kong_loo]

Hi - I am a bit confused by this.

Could you tell me with regard to the pump pressures being 225psi on the M3 nozzle - does this mean that because the nozzle size calculator assumes 100psi that I should roughly divide the nozzle size generated by the calculator by half?

Ie. if the calculator recommends I use a 6GPH nozzle but I am using a smaller 3GPH nozzle then I only in fact need a 3GPH nozzle?

Many thanks.

[pacemkr86]

i wonder what it is with dual m-10's

[contraption22]

Originally Posted by Kong_loo

Hi - I am a bit confused by this.

Could you tell me with regard to the pump pressures being 225psi on the M3 nozzle - does this mean that because the nozzle size calculator assumes 100psi that I should roughly divide the nozzle size generated by the calculator by half?

Ie. if the calculator recommends I use a 6GPH nozzle but I am using a smaller 3GPH nozzle then I only in fact need a 3GPH nozzle?

Many thanks.

Bump. Anybody have an answer to this? Thanks!

[contraption22]

bump

[dvldoc]

I had posted about this in the nozzle selector section a while back.

Flow does not work like people think, It does not double just because the psi doubles. Years ago I thought the same way until finding out from the makers that is not the case.

This is closer to what the nozzle put out, But it depends on voltage output of your vehicle.

M2 230psi = 2.9GPH
M3 225psi = 4.2GPH
M4 215psi = 5.5GPH
M5 190psi = 6.7GPH
M7 180psi = 9.0GPH
M10 170psi = 12.5GPH

20psi increase above 200psi on a 2GPH nozzle is around .1GPH increase in flow. at 200psi it is 2.7gph at 240psi it is at 3.0gph, 300psi it will flow 3.3gph. Many assume if you douple the pressure you double the flow but it's not correct.

[contraption22]

Thank you.

Now, with the latest kit it is my understanding that the pump pressure switch is pre-set to shut off at ~150psi. So if the nozzle size calucator suggests a particular flow rate, and the nozzles flow rates are measured at 100psi, then the nozzle should be at least somewhat smaller than the caluclator suggests, correct?

[dvldoc]

Yes, just a tad under what the calculator states. Even though the pressure switch cycles it cannot do it fast enough to cause a drop in the pressure in the line. It only fluctuates by about 10 to 20psi max due to the ID of the hose holding pressure.