Nozzle pressure?

[Geo-George]

Now, back to my original question:
What would be the required head/pressure to operate a 1 1/2 inch ( Keene ) suction nozzle?

[finegold]

This is a critical assumption as part of the answer, that the oriface is 13/32 or maybe 3/8 (12/32):
32 psi or 32X2.13= 68.16' of head (height of water above nozzle
and 2" pvc pipe for a length of up to 300' should result in a loss of only one pound.

Should result in approximately 31 psi (68.16' feet of head), at a flow rate of 25 gpm, through an oriface of 13/32. The biggest "IF" is that I have zero, nada, experience with a suction nozzle, only power jets. I do not know if there is a "reality" difference in requirements between the two.

A good place to start. If you can somehow measure the true diameter of the oriface in the suction nozzle you have, then I can adjust accordingly, but again based on power jet hydraulics not suction nozzles.

Knowing that a suction nozzle uses "x" for a pump, that has an awesome (manufactures brag) flow rate of "y", doesn't really tell you much of anything. Without an actual performance pump curve, for that specific pump and horse power, you are left with having to take a pressure gauge in line, crank it up the engine/motor to the performance you like, check the psi, and measure the flow.

[Geo-George]

Ah yes, experimentation.
I'll try the nozzle with 40' of head. If that doesn't work, I'll add another 10' of head and so on 'till I get the performance I like.
Thanks again, I really appreciate your input.
Geo-

[Geo-George]

Most smaller dredge pumps put out about a minimum of around 70 PSI and 90 to 100 GPM, bigger dredges will have higher PSI and especially higher GPM, I have seen homemade smaller dredges with pumps putting out 40 to 50 PSI and 90 to 100 GPM and work, but I would try to shoot for 60 to 70 PSI and at least 80 to 90 GPM. IMHO


Skip

So Skip, what is the nozzle size you use at 40 to 50 psi?
Does nozzle size matter or are the requirememts about the same regardless the size of nozzle?
I'm guessin' the required psi would be the same no matter the nozzle size.

[Gold Seeker]

George,

I have seen 2" and 2 1/2" nozzles work and be relatively effective at 40 to 50 PSI with around 90 GPM.

I don't know all the science or formulas has to how they work I just know what I seen and the specs on the pumps used.


Skip

[Geo-George]

Thanks Skip, every bit of info really helps.
I'm gettin' closer to a solution all the time.
Geo-

[Geo-George]

My many thanks to Skip ( Gold Seeker ) and finegold. You guys are tops in my book.

O.K., here's what I've come up with after sittin' down with a calculator and a topo map covering my claim.
To get a little over 50 psi, I need to run 400 ft of pipe which will give me 120 ft. of drop.
This will probably take me a full day to lay out. I"ll build a small dam and place a screen about 2 ft. from the upper end of the pipe, gotta keep the debris out.
Nuthin' worth while is ever easy. I'm gettin' more excited all the time, just havin' sumpin' to do.
..and I've got the greatest view with fresh water, Brook Trout, Pine, Cedar, and Cottonwood trees, and
my wife is the best dang campfire cook you could ever want. Ain't life grand.
And who knows, I might get some good color too.

Thanks again,
Geo-

[Geo-George]

I got in contact with Mark Keene of Keene Engineering, he wrote me back and stated that I would need 50 gpm and 100 ft of head pressure in order to operate my 1 1/2 inch nozzle effectively.

Well, that settles the issue for me, once and for all.