3 replies to this topic

[demank]

Dear all,

I want to calculate Brake Horse Power from Hydraulic Horse Power.
Branan Rule of Thumb state the equation for pump efficiency but range applicability is 100 ~ 1000 GPM.
It also state that 25~ 30 GPM pump efficiency is below 10.

My concern is when the flow rate is 8 GPM, how to estimate this efficiency?
Any literature for this?
Thanks in advanve before..

[JoeWong]

Try Estimate Pump Efficiency base on Specific Speed (Ns).

[demank]

Hallo,

I just calculationg that equation and graph.
And found that graph give a 500 rpm with efficiency about 20%.

Then my next question. 20% efficiency is not good.
Any pump vendor that have a single stage centrifugal pump which can deliver liquid about 8 gpm and head 90 ft?
(with pump efficiency above 50% of course)

[ARAZA]

Be Practical.

Always go with a lower efficiency during intial design since you tend to overdesign your electrical system a bit. The efficiency values could be verified after you get a firm quote from the vendor.

In your case, the BHP is either 1 for 20 % efficiency and 0.4 with 50 % efficiency. Figure it out, which one you will choose.

ARAZA