# Need Formula

1. Aug 5, 2004

### Eng_Luqman

Need to know the formula that i can use it to choose Water Pump ... or suitable ((( Water Pump ))) For any water pip line

if i have known water tank capacity

if i have two water reservoirs and need both to not to reach empty conditions

2. Aug 10, 2004

### Phobos

Staff Emeritus
Can you describe the system a bit more? Pumping from where to where? How fast? How much water? How far (horiz & vertical)?

Perhaps the Bournoulli Equation? Figure out how much of a pressure head you need and then check pump ratings that can handle that.

3. Aug 10, 2004

### Staff: Mentor

...and generally, using the info Phobos mentioned, you'd pick a pump straight from a performance graph. The only math is in calculating the head.

4. Aug 11, 2004

### Artman

Is this an open system? Are both tanks at the same elevation? Where is the pump in relation to the tanks?

The elevation of the tanks and their location relative to the pump is important in an open system, which is a system open to the atmosphere.

If the system is open, you need to calculate:

The suction head (height of the water in the tank relative to the pump inlet, the suction pipe friction losses including the pipe fittings and valves

The discharge head (height to the discharge opening in the discharge tank relative to the pump outlet, the discharge pipe friction losses including the pipe fittings and valves).