CUTWATER? 1

[imatasb]

Hello,

I came across the word Cutwater today and I have never seen before talking about pumps. (I think it's like an american word)The meaning is not very clear to me. Could someone just explian what is the cutwater?

Thank you

 

[TenPenny]

Cutwater refers to a part of a centrifugal pump...there is part of the casing , next to the discharge, that comes down close to the impeller....as the liquid rotates with the impeller, this nose "cuts" the stream of water, and deflects it into the discharge.

Hard to describe without a picture. I'll see what I can find.

 

[hydromech]

The cutwater is the bit of a centrifgal pump that seperates the liquid coming in from the liquid going out.

It is usually at the beginning of the throat of the pump...

Imagine the circular area that the impellar runs in...

The edge of the discharge throat of the pump is at a tangent to that circle...

Where the throat meets the circle is the start of the cutwater, from that point the cutwater tapers outwards to make a wedge shape.

Adrian
Concentric Pumps Ltd

 

[Cheddarcaveman]

The "cutwater" is located in the discharge casing of a centrifugal pump and it directs the product discharge from the impeller into the discharge volute. Along with the impeller, the cutwater can suffer damage from cavitation.
If you find that the impeller is worn (pitted) from cavitation, check the cutwater as well as if damaged it can lead to strange vibrations.
In a volute pump, the cutwater should start exactly opposite the casing leading to the discharge nozzel to ensure balanced flow or again you may experience unusual vibration.
(I wish one could attach pictures to these postings!)

 

[imatasb]

Thank very much for the explanation.

As Chedarcaveman says it is a pity that no pictures can be attached. A picture would probably make the explanation a lot easier.

Thanks

 

[rmw]

Let's put it this way. Say your finger got hung in a pump impeller and your hand traveled around part of a revolution as the impeller rotated. Where would your finger be cut off? That is the cutwater.

rmw

 

[Cheddarcaveman]

Ugh! Gruesome! That's a pretty sick answer!

I have contacted the forum host to ask if and how one could attache a picture.
Meanwhile Imatasb, email me at cheddarcaveman@yahoo.co.uk and I will attach a picture for you from my pump lectures explaining this.

 

[BigInch]

See thread378-184348: "Parallel" Pump Head Calculation: "Parallel" Pump Head Calculation for how to post diagrams.

BigInch-born in the trenches.

http://virtualpipeline.spaces.msn.com

 

[Cheddarcaveman]

Hey BigInch - How did you get that picture on the listing? I've asked the forum admin but they don't reply!!

 

[Tmoose]

http://www.tappsa.co.za/archive2/Journal_papers/Minimising_pressure_pulsations/minimising_fig_5.jpg

 

[vpl]

Cheddarcaveman

When you write a question or reply to one, there is some writing below the message box. It says "Step 2 Options". One of the options is "Process TGML." If you click on it, a separate box will come up (or should). If you scroll down through it, you will find instructions on how to include diagrams in your postings.

I updated FAQ731-376 to include a reference to posting pictures (see item 13)

Patricia Lougheed

Please see FAQ731-376 for tips on how to make the best use of the Eng-Tips Forums.

 

[BigInch]

[COLOR=red white] CAVEMAN !!! [/color]

Click on the following link. It will take you to a thread where I have given exact instructions on how to post a diagram. Scroll down to the picture. Just above the picture you will find an example of everything you need to do to make a diagram posting.

I already posted this link above, but here it is again,

CLICK ON THIS NEXT LINE!
thread378-184348: "Parallel" Pump Head Calculation:

BigInch-born in the trenches.

http://virtualpipeline.spaces.msn.com