Practical way to get Impeller Diameter 1

[ebermudez]

I have my pump's curve from a KSB -RPK/HPK-Y pump, and i've already plot my system curve, but I dont know and havent found the actual impeller width of my pump. I dont know if it has been modified in any way. In order to get the operation point of the system, I need to know the impeller diameter in such a way to choose from the pump curves the corresponding curve of the actual impeller diameter.

Do you know any practical way to get the impeller diameter?, since i dont have any way to measure the actual flow.....
I would appreciate very much your valuable respond.

EB

 

[electricpete]

Operate at shutoff for very brief period and measure head?

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[electricpete]

... of course need to review this to make sure you're not going to damage the pump

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[ebermudez]

I dont get your point!, would you explain me the operating at shutoff, and how could I measure head in that condition. What do i need to review to make sure i dont ge to damage the equipment.

Im a new grad, im trying to learn all this, and also trying to get my job done. Thanx for your interest...

EB

 

[Artisi]

It sounds to me as if this is an existing operational pump - if this is the case simply measure the flow under operating conditions to give you the pumps performance.

Working from your curve will at best only give you a calculated theoretical performance not the actual site performance.

However, if for some reason the impeller diameter must be known, the only reliable way without access to the information from your own records or from the supplier, is to dismantle the pump and measure the impeller diameter, nothing else will give you the correct answer.



Naresuan University
Phitsanulok
Thailand

 

[pumpkind]

Most pumps sold for dedicated duites have their Impellers cutted to fit the duty.
There are few ways to find out - I do not know how accurate you wanna be.
1. If the pump has a nameplate - the diameter of the fitted impeller is normally stamped on the nameplate.
2. Roughly speaking, you can guestimate the diameter of the impeller by inserting you duty point - (i.e. volume and head )onto the book pump curve - which you said you have.
3. Send an e-mail to KSB with Pump reference serial number (stamped on the nameplate but also on major components such as casing ) and they will have this information on their records.
Hope this help

 

[Artisi]

The information from pumpkind is valid provided you are certain of the pumps history - ie , is the impeller still as supplied from the manufacturer or supplier. Assume nothing - if in doubt check first hand.

Naresuan University
Phitsanulok
Thailand

 

[ebermudez]

Thank you all for your support!. Electricpete, your suggestion kept my boss' attention, thats what he was looking for,he was testing me on that!

 

[sprintcar]

Why not just contact KSB and ASK them for the impeller dimensions??

"If A equals success, then the formula is: A = X + Y + Z, X is work. Y is play. Z is keep your mouth shut."
-- by Albert Einstein

 

[ebermudez]

'Cause I think the impeller had been altered already.

 

[hydrae]

So you want to measure the impeller diameter without taking the pump apart? Is there a pressure gauge port just downstream of the pump? how about a drain plug? vent plug? Priming line? Can you add said ports?

Use a fiber optic boroscope through any or all of these access points with the pump off and drained. Calibration of the sight would be done using a mock up to see the gap between the impeller edge and the volute casing or diffuser.

If you can also look at the eye and edges of the vanes for cavitation damage that would be helpful and might be the cause of the question.

Hydrae