I wouldn't use a suction nozzle on anything bigger than a 3' personally. One goes straight down the nozzle with no resitrictions, the other (in a jet) usually hits the side of the jet tube at some angle, dispersing energy.

If you look at the pressure line inlets in both a jet and suction nozzle I think you can see why.

There has been some studies done that show that using a suction nozzle in place of a jet connected directly to your flare actually has greater suction than a jet. So you won't rooster tail your sluice if you pull it out of the water.Īlso, there is some debate as to which nozzle has 'better' suction. With a suction nozzle, it's the nozzle itself being primed by the pressure line, and the pressure flow is directed right down the center of the suction line where it connects to the nozzle. Since the pressure line goes directly into the jet and into your flare you are going to rooster tail out high pressure water straight outta your box. I don't think it's cavitation proper, it's just that when you pull the nozzle outta the water when using a jet then you are going to lose the prime on the jet.

Gold dredge suction nozzle