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Required Orifice size to produce 15,000 psi

Posted: Wed Jun 23, 2010 4:42 am
by chirag412
Hello,
My family is trying to determine the required size of the Orifice for fan type nozzles.

Below PLEASE READ about our equipment and application to give you all a better understanding of what were are trying to do and allow you to suggest most appropriate nozzles.

We are normally using a 2500 bar (36000 psi) pump @ 26 liters a minute. The output device has six nozzles of 3/8" x UNF straight type . To achieve 36,000 psi pressure we generally use the following nozzles: 2 of size 0.020", 2 of 0.013" and 2 of 0.014" at 1800 Rpm of the pump.

Recently, we had tried to reduce the pressure on our pump by using larger straight type nozzles for rubber removal from runways. With size 0.020" x 6 nozzles at 1,800 Rpm the pressure reduced to 14,000 psi. With size 0.034" nozzles X 6 nos we could go down to 4,500 psi. But these pressure range was reached using 'straight' type nozzles. This was causing too much impact to runway surface -so we are actually interested in using fan tip nozzles.

Therefore, we are actually interested to use fan type nozzles to suit our application of removing rubber from runways and would like to reduce the pressure on our same pump to 15,000 psi by using fan tip nozzles.

Based on our understanding we think we will need the following:
Size
0.022"
0.024"
0.026"
0.028"

Are these correct? Based on your experience and understanding of our application what sizes of fan type nozzles should we use?

I also wanted to know that if we keep our pump pressure constant 36,000 psi (i.e at 1800 RPM of the pump) and if the flow rate is 26 liter per minute - if we use bigger size orifice nozzles - would we see a lower output pressure ? Who would be calculate that ?

Thanks.
CKS

Re: Required Orifice size to produce 15,000 psi

Posted: Thu Jun 24, 2010 7:19 am
by admin
I am not a person that can help you on proper nozzle selection, but maybe you can use of this: http://www.lechler.de/pdf/4_flachstrahl_e.pdf.

Now, if I understand you correctly, you control the pump flow rate with rpm of the pump. With increase of flow rate, the pump pressure increase. To know the pressures you must tell me the value of coefficient of discharge for nozzle. This number should be constant for one type of nozzle. If you change type of nozzle it will change. If you change diameter of nozzle, for the same flow rate (rpm), pump pressure will change - with diameter increase - pressure will drop and vice versa.

I am not sure if it helps, but that is all from me.