waterjet

[aryanboy]

I have two question:
I want to know what is the difference between one stage waterjet and two stage waterjet?
and what is the difference between waterjet that is work in salt water and waterjet that is work in fresh water, and which of them is better?

[Submarine Tom]

1. I don't know
2. Sea water jet, the water is more dense.

[mreoe4sure]

aryanboy, If you go to the Hamilton pump website, it will show you different pumps, one ,two, three stage pumps. If is am correct, I used to work with single stage, two stage centrifugal pumps. the outlet of one pump was connected to the inlet of the next pump thus doubling the pressure output. On the hamiton website you will see that it looks like they bolt more section together to add more stages. I would think the difference in pumps between salt and fresh water is what they are made of, for corrosion. Someone else knows more on this site and they might help if I am wrong.. Steve

[aryanboy]

@mreoe4sure You know we want to buy a waterjet,I checked hamilton jet before but it doesn't have waterjet that is use in small size boat, by your answers you mean that the two stage waterjet and waterjet that is work in salt water is much better so the price of them should be higher.
thanks for your help and advice.

[anthony goodson]

Jets work equally well in salt or fresh water ,salt water may be heavier than fresh ,but you wouldn't notice it carrying a bucket full and a jet certainly wouldn't. Corrosion can be an issue but as long as the appropriate anodic protection is in place this is manageable. What size weight and hull form is your boat,and more importantly what are the special operating conditions which would lead you to fit a water jet ? Why ?,not which ? is a far more important question at this stage.

[aryanboy]

we want to make a jet sprint boat so as the size be smaller is better for us and it just carries two crew persons.the maximum size of our waterjet should be 8.5 inchs in diameter and just this limitation is in our waterjet , the hull of the boat should be made by aluminum and the engine can have 8 cylinder with maximum volume of (6,752cc) or 412(in*in*in) and the min is 354 (in*in*in).
so know what's your advice gentleman?

[anthony goodson]

aryanboy ,jetsprint is a unique and very specialised area of jet boat design ,you may learn a lot more on one of the forums dedicated to just this , Google jetsprint and dozens come up. I think somebody tried to introduce it here in the UK ,but it seems to have come to nothing. Perhaps some of the guys from NZ on here may be able to help but I am sorry to say I know very little about it. Good luck anyway ,and buy some life insurance.

[faezeh]

I have two question:
I want to know what is the difference between one stage waterjet and two stage waterjet?
and what is the difference between waterjet that is work in salt water and waterjet that is work in fresh water, and which of them is better?

[daiquiri]

Now what was that?

[Submarine Tom]

Originally Posted by Submarine Tom

1. I don't know
2. Sea water jet, the water is more dense.

Okay?

-Tom

[RivrLivn]

Question 1) the simplest explanation is the number of impellers. A single stage has 1, a two stage has 2, and a three stage has 3. With the multistage units the pitches will usually be varied. The purpose is to keep the pump loaded in all conditions. Also takes more power to turn more impellers.
Question 2) the main difference will be the materials used on the unit, aluminum, brass, stainless, and of course the number of sacrificial anodes.

I'm sure others will correct where needed.

[jbmboats]

you need a scott 852 2 stage water jet for your sprint boat
they are the best out there and hold all the world titles to show for it
and can have the impellers pitch to match your hp
www.scottwaterjet.com

[faezeh]

I want to know dose the waterjet that works in salt water is usefull in fresh water?

[Submarine Tom]

Yes of course.

-Tom

[aryanboy]

thank you so much jbmboats.
but this moddel can be use in group A engine?
I saw that it would for superboat engine