Hvac Pump Head Calculation Pdf Fixed Download
Identical pumps will develop the same head when running at the same speed but the discharge pressure is quite different due to the different densities of the liquids. It can be simpler to discuss the performance pumps in terms of head rather than pressure since the use of head makes the pump curve applicable to any liquid regardless of density.
hvac pump head calculation pdf download
The highest height at which a pump can convey fluid against gravity is called the head. If you have a vertical pipe running straight up from the discharge exit, this is the clearest example. Fluid will be pumped up the pipe 5 meters from the discharge exit by a pump with a 5-meter head. A pump is an important Product of employing Industrial Tools. Pumps are provided by several Suppliers and Companies, different manufacturers, and a lot of distributors and there are a lot of pumps for sale on Linquip.
Sometimes the head can be confused with pressure during pump choice. There is a strict relation between them which is defined by the fluid specific gravity, so the relation is fluid dependent. So what is the difference between pressure and head?
As mentioned above, Head is the height given by the pump to the fluid and it is measured in meters of liquid column [m.l.c.] or simply indicated in meters [m]. The given head is fluid independent, meaning different fluids with different specific gravities are all lifted at the same height. Pressure, instead, is fluid dependent and is affected by the liquid density. The force of a fixed height liquid column over a unitary area will change with different specific gravities. So in this case the same head generates different pressures.
The pump head calculation is not done directly. Manometers on the pump suction and delivery line give the measure of the pressure. Measurements given by manometers indicate differential pressures imposed by the pump between suction and discharge. These measures are read in [bar] [atm] [psi] [ft H2O] etc. Specific gravity γ has to be considered to evaluate the correspondent head.
Conversely, if the pump is located above the water to be pumped, then the suction head is positive and the pump head will decrease. This is because the pump must use energy to bring the water to the level of the pump.
At the maximum pump head, the flow of a water pump system is zero. This is because the pump cannot generate any pressure to move water since all of the power is being used to lift the water that is already in the system. 350c69d7ab