How to calculate the flow rate and pressure of the water pump?

In some places, the acquisition of a water pump is not a luxury, but a fundamental necessity for the operation of the home, however, due to the large number of options available in the market, it may be difficult to choose one, especially all because it is not so easy to know what is the flow rate and the pressure that it should have according to each case.

Water pumps are basically generating machines, which are capable of moving a certain amount of water in a short time and without much effort on the part of the user, either to transport it from one place to another or extract it from wells, cisterns or swimming pools, among others.. They are widely used in rural areas where people collect drinking rainwater for domestic use, as well as in buildings where it is necessary to raise the water several meters above the ground, but they are also useful when large amounts of product water must be removed. of a flood.

The best water pumps of 2022 are designed for certain specific needs, however, almost all of them share the main function, which is the same as any hydraulic pump, that is, to convert mechanical energy into kinetic energy, moving the liquid from one place to another. other. In fact, there are pumps to move milk, wine and other beverages.

In general, the water pump is made up of two holes, one for inlet or suction and the other for outlet or impulsion. Formerly, this process was carried out manually using a lever and later wind energy was used through windmills with blades, which extracted water by moving it from one place to another for irrigation of crops and human consumption.

Among the most common today are the electric pump and the motorized pump; the former uses electric current as a power source, while the latter has an integrated motor and runs on gasoline or diesel. There are also pumps that work with external aids, either pulleys or shafts.

Lo buenoLo MaloConclusiónOfertas

Programador de riego

SHIMANO Fahrradschuhe XM Radschuhe SH-XM7 GR. 45 SPD Versenkt Gore Tex Vibram, Zapatillas de Ciclismo Unisex Adulto, Gris, EUVer Oferta del Dia
Ver precio en Amazon.es
Lo bueno

Lo Malo

Conclusión

OfertasVer precio en Amazon.esLeer más

Aspersor oscilante

Asvert Zapatillas de Ciclismo Carretera Unisex Profesional con Plantilla Antideslizante Amortiguador para Bicicleta al Aire Libre (44, Blanco Rojo)Ver Oferta del Dia
Ver precio en Amazon.es
Lo bueno

Lo Malo

Conclusión

OfertasVer precio en Amazon.esLeer más

Manguera para riego

Sidi SID17003_87985, MTB Buvel Zapatillas 2017, Negro, Talla 42 Mujer, Nero, EUVer Oferta del Dia
Ver precio en Amazon.es
Lo bueno

Lo Malo

Conclusión

OfertasVer precio en Amazon.esLeer más

"}» data-sheets-userformat=»{"2":14915,"3":{"1":0},"4":[null,2,16777215],"9":0,"12":0,"14":[null,2,0],"15":"Arial","16":11}»>

Basics when selecting a water pump

If you have already decided to buy a water pump, it may be convenient to think about several fundamental aspects to define your true needs before choosing one or another model. First of all, it is good to think about the type of water you want to pump, because if it is dirty water, for example from a septic tank, then a special submersible type pump will be necessary, while if it is clean water such as that of a swimming pool, almost any pump can serve you.

Another characteristic of great importance is the origin of the water. To extract water from a lake or river you will need a surface pump, but there are two types, one that works above the water level, known as a suction pump, and another that must be installed at a level lower than or equal to the water..

It would only be necessary to define the power that the pump must have so that it has optimal performance. In this sense, it is necessary to calculate the nominal flow, which is nothing more than the volume of water required in a certain period of time and is expressed in liters per hour (l/h), to obtain this data we must take into account the needs of your house and your own components. In addition, it will be necessary to measure the manometric height, which is expressed in meters of water column (mwc).

Calculation of the necessary flow for your house

There are some basic estimates that we can take as a reference to know which water pump to buy depending on the flow rate that we need at home or at work. If it is a house with a kitchen, laundry room and a toilet, then about 2,000 liters per hour will be enough. In those houses that also have a bathroom, the approximate flow would be 2,800 liters per hour, while if it has a full bathroom, approximately 3,600 liters per hour will be necessary.

In those homes that include a kitchen, laundry room, bathroom and toilet, 5,400 liters of water per hour are recommended. However, if you have these rooms plus another full bathroom, you will probably need approximately 7,500 liters per hour so that you do not have problems with the distribution.

The manometric height (HG) is one of the most important data we need, for this we must add the suction height (Ha) and the discharge height (Hi), the formula would be as follows: HG=Ha+Hi. The good thing about doing this calculation is that later we can compare it with the number of liters we need to move to choose the corresponding model from the tables that most brands include in their product catalogs.

On the other hand, if you have irrigation facilities, then you must take into account the amount of water that each sprinkler needs. The 90º diffusers need 540 liters per hour, while the 360° diffusers need 1,020 liters per hour. In addition, the jet diffusers consume about 900 l/h. With these data, it is possible to know the amount of water that we must pump.

Suppose you want to move the water from a cistern to a higher place to obtain a flow rate of 2,500 l/h. In this case, it is possible to calculate the loss in mca, using the pressure drop table. If it is the mentioned flow in a 25 mm pipe, we would be before 9.4 m for every 100 m. When calculating 20 m of suction pipe, the equation would be 9.4 x 20/100 for a suction head loss of 1.88 mca. If the delivery pipe is 75m long, we would work with the same equation, 9.4 x 75/100 to get 7.05m head

The formula is Suction height + Delivery height + Suction pressure drops + Delivery pressure drops = Total manometric height. Using as an example data a suction head of 2 m and a discharge head of 20 m, the corresponding calculation would be 2+20+1.88+7.05, to obtain 30.93 mca, corresponding to the total manometric head. Therefore, we would have to select a water pump that lifts 2,500 liters per hour to a height of 30.93 mca.