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# flow of pipe from absorbed current

## flow of pipe from absorbed current

(OP)
Dear all,
I would like to know if it is possible to know the flow in a water pipe from the value of the absorbed current of the pump installed on it.

Regards

### RE: flow of pipe from absorbed current

what do you mean by current... electrical current?

=====================================
(2B)+(2B)' ?

### RE: flow of pipe from absorbed current

You need to know voltage, pressure, power factor and efficiency.

voltage x current x power factor = power

efficiency x power/pressure = flow

I used to count sand. Now I don't count at all.

### RE: flow of pipe from absorbed current

(OP)
Thank you very much for the help!

Giuman

### RE: flow of pipe from absorbed current

Yes you can but it'd not very accurate, probably 10 to 15% at best.

Easiest way is to find the pump curve. Note that the power on a pump curve is shaft power not motor inlet power. You also need to know motor efficiency to change electrical power to shaft power.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

### RE: flow of pipe from absorbed current

I am agree with SandCounter but let me make it more precise;
Power Input (KW) * 1000 = Power Factor x Current (Amps) x Voltage x (Phases Numbers)½

This power is Input Power to Motor, so you need to know the motor efficiency in order to know the Output Power from the motor which is the Shaft Power (BHP) which is the input power to the pump.

by knowing the BHP then you can use below equation to get out with your Q (flow-rate)
BHP (KW) = (9.81 x Q(m3/s) x TDH (m) x S.G / Pump Efficiency)

I also agree with LittleInch regarding the unaccuracy of the resultant come from the calculation above, nevertheless I didn't agree on the divergent percentage (I think its low than this percentage).

Mohd Yaseen

### RE: flow of pipe from absorbed current

It is difficult enough to get accurate pump performance data in an installation using the proper measuring equipment, so trying to establish flowrate from current input will be neigh on impossible.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

### RE: flow of pipe from absorbed current

Mohd,

Thanks for filling in the gaps, especially on the electrical side.

I used to count sand. Now I don't count at all.

### RE: flow of pipe from absorbed current

Going back to Mohd's post re calculation.
Rightly pump efficiency has been included in the calculation - can we assume the OP has a pump curve to establish efficiency, if that is the case then the OP can after calculating the input power to the pump you can read off the approx. flowrate from the HQ curve - about as accurate as any other guess work establishing flow.

Without having the pump efficiency - there is no way the flow rate can be established.

It would also be interested if the OP is talking about a 1kW or 1000kW pump unit.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

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