determining centrifugal pump flow rate
determining centrifugal pump flow rate
(OP)
Please i'd like to know how you can determine the flow rate of a centrifugal pump that you don't have any characteristics,by knowing only:the pressure of the delivery of the pump (2,3 bar), the size of the pipe (50mm diameter),the material (NaOH solution with specific gravity of 1,2 kgr/lt).Is there a formula to calculate the flow rate or is something else needed?
Thank you in advance everyone
Thank you in advance everyone





RE: determining centrifugal pump flow rate
RE: determining centrifugal pump flow rate
If you know the pump, you can get a copy of the pump curve and estimate the flow based on the head produced by the pump. BUT, if you have a flate pump curve, you will have a high degree on uncertainity in your answer.
If the discharge piping is long, you might be able to calculate a flow rate if you can measure the pressure drop. If you have a control valve in the system and can determine what % open it is and therefore the Cv off the valve data sheet, that's another method but all of these have typically a fairly high degree of uncertainity in them.
RE: determining centrifugal pump flow rate
Best regards
Morten
RE: determining centrifugal pump flow rate
Sometimes it is possible to measure the flow rate by breaking a joint and measuring the flow rate using the time honoured "bucket and stopwatch" method.
The pump may be drawing out of a tank. Perhaps you can isolate the inflow and time the tank drawdown. By measuring the tank dimensions, the flow can be calculated.
Another way is to measure the "product" made by the solution. For example if the solution is used to neutralize and acid, and the acid rate is known, then the solution rate can be calculated. Alternatively, perhaps you know how much caustic is purchased per month and how many hours per month the pump runs.
If the pump is feeding a ringmain which returns to the feed tank, this complicates things, as the return flow must be diverted, and measurements made.
If you post the make, model, speed and motor power of your pump someone may have a curve or two.
Cheers
Steve
RE: determining centrifugal pump flow rate
Similiar to TD2K's method,
if pipe line is long enough ,put a pressure gage ,find the pressure drop (Pa/m) then using friction loss table find the flow rate .
of course it doesn't give a precise results
Ercan
RE: determining centrifugal pump flow rate
International College
Naresuan University
Phitsanulok
Thailand
RE: determining centrifugal pump flow rate
For. ex. : 2.5*(3.1416*0.05^2/4)*3600 = 17.7 m3/h (checking the result with nozzle size).
Anyway I shold prefer to refer to nozzle size.