Pump Data giving more discharge than assigned in Pump Definitions

What exactly do you mean by "pump data giving more discharge than assigned in Pump definitions"?

If you specified that the rated flow is 400 gpm at a head of 100 ft, but the pump is discharging against 50 ft of head, then the flow will be greater than 400.

Thanks for your reply. I got your point. I want to run my model by fixing discharge of pump or by fixing head of pump. Is this possible ? 

To force a flow from a pump, make it a negative demand. To force a head, make it a reservoir. However, you'll need to check to ensure that they are operating at a feasible point on the pump curve.

SR, please see the following related article from our Wiki about how Pumps work:

How are pumps handled in each OpenFlows product?

If there are only fixed demands downstream then the pump flow will be equal to the sum of those demands, but if there is storage (tank) or other complicated factors downstream, the pump will operate somewhere on its defined pump curve. This is based on where the pump curve intersects the System Head Curve (see above article). A pump will add a certain amount of head in order to overcome static (elevation difference) and dynamic (headloss) head between the suction and discharge side for the given flow rate.

If you really do have a pump in your system and the model shows that it is not operating at the expected point, then there could be a problem with the data entry, or some difference between the real system and the model. In that case, rather than just forcing the model to show you the flow that you want with a negative demand, you may need to look into why the model is giving a different result than the observed/expected result, which may reveal a data entry issue that otherwise would have skewed other model results.

SR, please see the following related article from our Wiki about how Pumps work:

How are pumps handled in each OpenFlows product?

If there are only fixed demands downstream then the pump flow will be equal to the sum of those demands, but if there is storage (tank) or other complicated factors downstream, the pump will operate somewhere on its defined pump curve. This is based on where the pump curve intersects the System Head Curve (see above article). A pump will add a certain amount of head in order to overcome static (elevation difference) and dynamic (headloss) head between the suction and discharge side for the given flow rate.

If you really do have a pump in your system and the model shows that it is not operating at the expected point, then there could be a problem with the data entry, or some difference between the real system and the model. In that case, rather than just forcing the model to show you the flow that you want with a negative demand, you may need to look into why the model is giving a different result than the observed/expected result, which may reveal a data entry issue that otherwise would have skewed other model results.