The wide variety of water pumps offered by the current market poses a great challenge to us when choosing the most suitable for our purpose and, at the same time, which is suitable for our budget.
It is not the same to choose one bomb To extract dirty water from a flooded basement, for example, we have to select a pump for a decorative fountain in our garden or to irrigate a field in an area that lacks electricity supply. The requirements are different and most of the cases involve a series of mathematical calculations that will help us find the correct characteristics.
However, without going into these calculations and for the purpose of facing a first guiding article about the choice of water pumpsWe are going to focus on the characteristics that are common to all types of pumps and the essential questions we must ask ourselves, regardless of the end use of the pump.
Typical parameters of water pumps
To know what is the first thing that we must ask the seller at the time of purchase, it is essential that we previously know a few terms that define the properties of a water pump. These terms or parameters are as follows:
Discharge capacity: is the rate at which the water flows from the source to the point of discharge, measured in gallons (GPM) or liters per minute (LPM). Provides the energy to move the water quickly.
Vertical suction lift (see figure below): it is the vertical distance from the water source to the pump. This is important for draining a basement or deep pond, for example and, as we will see later, it gives us an idea of the horizontal length that the suction pipe should have.
Maximum height (see figure below): it is the total height from the source of the water to the destination or drainage point. This provides the power to move the water over a set vertical distance.
These parameters that we have just seen are the ones that will give us answers to two fundamental questions:
- How much water pressure do we need?
- What flow of water do we need?
Water pressure is a measure of the force that pushes water through the supply network and into your pipes. It is measured in bars, where one bar is the force necessary to raise the water to a height of 10 meters.
The water flow depends on the size of the pipe. If a single pipe has multiple taps and other connected devices, the flow rate will be lower and there may not be enough water in the pipe to supply all devices at the same time.
Older homes typically have ½-inch diameter water supply pipes, which can cause problems, especially when it comes to converted apartment homes. Modern houses and apartments tend to have larger diameter pipes (1 inch) and this allows a more abundant flow and a greater number of devices in simultaneous use.
As an example, the following table details typical household water consumption. In fact, this will always depend on the number of inhabitants. For example, if two people live and the house has 3 showers, the water flow demands will be lower than if there were 4 people living using all the taps at the same time.
If, for example, we simultaneously use a shower, dishwasher, washing machine and toilet at the same time, the total water demand can reach 44 liters per minute. All this data can give us an idea of the flow we need in the pump.
Regarding the calculation of the necessary water pressure, whose normal values for domestic water range between 2.8 and 4.8 bars, it is convenient to ask the following questions:
- What is the difference in height between the water source and the highest point of use, that is, the maximum height?
- Is the water source below the pump? Or, what is the vertical suction lift and what horizontal distance must the water travel?
- What size, type and length is the pipe used from the pump to the final destination?
- What is the source of the water?
Most of these questions can be solved using the following diagram (measured in feet).
So, for example, if we choose a bomb With a vertical suction lift of 10 feet, the length of the horizontal suction pipe should not exceed 72 feet to minimize friction losses.
Another question we must ask ourselves is: Is electricity available? This presents us with two great possibilities: choosing, among the most common, an electric pump (or electric pump) or a fuel pump (or motor pump). Both have their advantages, but each is suitable for specific uses. The electric pumps they are frequently used indoors where electrical outlets are readily available. Typically, they are less powerful than fuel models. However, they don’t require a lot of maintenance or oil changes. Optionally, if we do not have electricity and the circumstance supports it, we can purchase a portable generator to power our electric bomb.
For their part, motor pumps They are not limited to cords and outlets. They are the perfect solution for outdoor jobs and tend to offer a higher discharge capacity than their electrical counterparts. However, using these pumps indoors is dangerous due to carbon monoxide emissions.
Other considerations to take into account
If our Water Pump you are going to stay in the same place most of the time, your weight may not be a relevant element at the time of the election. But if we have to move the pump to different places with a certain frequency, a lightweight design is important. Therefore, let’s take into account the total weight, as well as the material that makes up the pump.
Pump construction material
Aluminum is a light, malleable, and ductile metal that has good electrical and thermal conductivity, high reflectivity, and resistance to oxidation.
Brass or bronze has good strength, excellent high-temperature ductility and reasonable low-temperature ductility, good conductivity, very good corrosion resistance, good strength properties, and low magnetic permeability. Sintered bronze is a porous material, which can be impregnated with oil, graphite or PTFE. Not suitable for heavily loaded applications, but useful when lubrication is not convenient.
Cast iron does not refer to a single material, but to a family of materials whose main constituent is iron, with considerable amounts of carbon and silicon. Cast irons are natural composite materials whose properties are determined by their microstructures, that is, the stable and metastable phases formed during solidification or subsequent heat treatment.
Plastics are any of various organic compounds produced by polymerization, capable of being molded, extruded, melted into various shapes and films, or drawn into filaments used as textile fibers.
Stainless steel is resistant to chemical corrosion and may be suitable for relatively high pressures.
Type of motor
When it comes to the operation of the Water Pump, the engine is a significant feature to consider. Many pumps are equipped with an overhead valve (OHV) motor. Unlike older engines, which feature the valves in the block, these engines have valves located in the cylinder head, which increases their overall power and makes starting easier.
The motor pumps require oil to function properly. In some engines, checking the oil is a frequent requirement, as a low oil level can lead to engine damage. For this reason, some manufacturers offer their motor pumps equipped with sensors capable of detecting the decrease in the oil level that could alter the proper functioning of the equipment. When the sensor detects a low oil level, the engine automatically shuts down to prevent failure.
Components and functionalities
Some models of bombs They are equipped with silicon carbide mechanical seals. These seals are resistant to abrasions and extend the life of the pump.
The volute is a chamber where pressure is created from the energy produced by the impeller. As the impeller pushes the water into the volute, enough pressure is created to propel the water toward the discharge point. Many models of bombs They are equipped with a cast iron scroll. This material helps reduce wear and tear on the chamber and improves the longevity of the water pump.
On some models, a high-performance mount is used to reduce the vibration the pump experiences while operating. This offers many benefits, such as reduced wear on pump parts. It also reduces the chances of equipment being buried or moved from the site.
The submersible pumps They can be used for temporary flooding, but may also be necessary to move water from one place to another on a continuous basis. For this reason, many submersible pumps are designed for continuous use, that is, they can run all day and every day without risk of overheating, as long as they are kept in the right environment and the ambient temperature does not exceed 40 ° C. Safety is an important consideration in selecting a pump. When it comes to submersible pumps, let’s avoid mercury float switches, which can be dangerous to our health and the environment. Instead, buy models with mechanical float switches.
A Water Pump It may be stocked with all the parts we need to get started right away, or we may need to purchase some additional accessories to take advantage of all the uses of the pump. Here are some accessories that we may need.
When transferring water from one place to another, being able to connect the bomb directly to a garden hose is essential. This can be especially useful when using the pump to water the lawn, garden or field. If this is the case, let’s make sure that the pump we choose has a kit that includes, at least, a garden hose adapter or coupling, clamps, a filter and a suction hose.
There are two types of adapters available: the “pin lug” type and the “camlock” type (see figure below). The hoses with “pin lug” adapters work like a traditional garden hose and are attached to the pump by means of a thread with the help of a suitable wrench. Hoses with “camlock” adapters are easily connected to the pump using a quick connect system.
It is also a good idea to invest in a couple of extra gaskets. These parts are frequently lost and are necessary for the kit to function properly.
Guide to a good choice
We have already mentioned the diversity of water pumps that we will find in the trade, where there is practically a type for every need.
Now, to summarize and complete this article, we are going to provide a comparative detail that advises the choice of the appropriate type of pump taking into account some of the characteristics and parameters that we have just seen.