Selecting agricultural irrigation pumps is a huge task because of their long-term use and costs. For instance, poor performance may have a direct effect to crop production. This could translate to thousands of dollars of lost income and productivity. In addition, the wrong choice of pump could even damage your irrigation system.
That’s why here in this article let’s discuss a few economical tips to make the right choice. Along the way we’ll also discuss other important things that relate to purchasing pumps for farming irrigation. Let’s start.
1. Know the flow rate and pressure requirements
A pump with an inappropriate or wrong flow rate and pressure requirements could lead to pump damage and expensive repairs. Rapid creation and destruction of small bubbles may occur. Some of these small bubbles may explode and damage the internal of the pump.
Whether you choose a centrifugal pump or a turbine pump, the pump duty (flow rate and pressure requirements) should still be the priority. Often the pump duty is shown through performance charts. These display the different pressure levels the pump creates at various flow rates.
There’s an inverse relationship between the pressure level and flow rate. As the pressure increases, the flow rate decreases. This information is very useful if your farm requires large volumes of water at low pressure. You can then choose the pump with the appropriate pump duty.
The numbers and relationship between the flow rate and pressure also show how efficient the pump is. For a given power specification (e.g. 7.5 kilowatt motor), is the pressure and flow rate acceptable for your particular application? The answer to this question could contribute to long-term savings on operating costs.
Take note that the motor is the component that gets the pump into action. The higher the power of the motor, the higher the pressure level that will result. However, its operation will require more fuel or electricity. Operating costs will rise and it may even significantly contribute to the wear and tear of the system.
It’s all about determining the desired performance and then choosing the option the best matches your objective. Other constraints such as costs also play a huge role in the purchasing decision. This is an engineering decision wherein you consider the constraints while still aiming for the best performance.
Another objective aside from maximising efficiency and savings is creating and maintaining uniformity in irrigation. Even with the addition of nutrients via the system, it should still perform uniformly and reliably to acquire consistent results. Inconsistent performance might make irrigation far from optimal or reproducible. To achieve a good level of uniformity, it’s also important to place equal importance on the irrigation design. Let’s talk about this next.
2. Irrigation design for uniformity
The pressure (which results from the pump’s power and performance) has a huge effect on how much water comes out of the nozzles. This also has effects on how uniform the irrigation will be. Sub-optimal irrigation design and selection of pump may result to varying growth rates among the crops.
This problem could be caused by operating pressures that are incorrect or inconsistent. This results to some areas of the land receiving little or no water. Another cause is the sub-optimal placement of sprinklers or nozzles. The spacing might be too far apart which results to areas being inaccessible to water.
This may require some testing because of the varying pressure levels, wind conditions, sprinkler specifications and other factors. The goal is to ensure that almost all concerned areas are receiving roughly the same volume of water during each irrigation session. One way to accomplish this is by strategically placing catch cans in a grid pattern. This is to check for any variation among the amount of water collected by the cans. Expect to see some variation but make sure it will be kept to a minimum especially during the active growth stages of the crops.
A good enough pressure level (thanks to proper choice of irrigation pump) can contribute to uniformity. In addition, this would somehow reduce the effects of possible distortion such as high wind speeds. Although it’s impossible to achieve 100% uniformity, it’s still a good step to maintaining a consistent growth among the crops.
Pump specialists and irrigation designers work on various specifications and constraints to attain the optimal result. There are cases when the constraints relate to the type of crops, season, coverage area and source of water. They also consider the energy source to power the pump’s motor. All these factors ultimately contribute to the long-term operating costs and productivity of the farm.
Irrigation design can still be modified any day to achieve better productivity and efficiency. However, the costs of rework (disassembling pipes and sprinklers & putting them all back together) would be significant. Moreover, delays and lost productivity will also result from the redesign of the whole irrigation system.
Also take note that replacement of pump systems might be required to make the system work more efficiently and ensure uniformity of crop growth. Perhaps a pump with higher power will be required to further distribute the water in the land. It’s also possible that a booster pump will instead be used to increase the water pressure and expand the reach.
3. Is it for a new or existing irrigation system?
An existing irrigation system may only require a booster pump to expand the system’s reach. The goal is to increase the pressure by boosting the current movement of water. The pump has already done the initial work which is moving water from an inactive source into the sprinkler system. The role of the booster pump then is to further push that moving water.
It’s often installed to complement the water from the local water supply. The pressure might not be sufficient enough or the area just has a lower water pressure. There’s always a pump working somewhere because it’s required to move water from the source into the output system. However, that movement may not be enough to satisfy our irrigation requirements.
Whether it’s a new or an existing irrigation system, installing a booster pump may successfully meet the desired irrigation performance. It can improve the “spray distance” and achieve a wider coverage area. Although there’s no guarantee that it will make the water sprinkling more uniform, the addition of a booster pump could contribute to achieving better irrigation and crop growth.
But before installing a booster pump, it’s important to optimise the current system first to avoid unnecessary expenses. We’ve discussed earlier the strategic placement of sprinklers and nozzles. Also, it’s recommended to check the condition of the pipes. Clogs and warping might be hindering the flow of water which thereby decreases water pressure. These are low-hanging fruits you can do first to increase water pressure and widen the coverage area (instead of purchasing new pumps that add further to your costs).
Selecting agricultural irrigation pumps
Irrigation designers and pump specialists also consider the possible pressure losses resulting from friction of the water with the pipes, valves and fittings of the irrigation system. They also consider the variation in land elevation and terrain. These factors can considerably affect the effectiveness of the irrigation and thereby your crop yield.
Reducing water consumption (while still achieving acceptable pump performance) is also a priority as well as minimising fuel or electrical usage. This is to further lower the long-term operating costs and at the same time getting the most out of every dollar invested.
Here at Truflo Pumping Systems we have a wide range of pumps for agricultural purposes. Our high-efficiency pumps are able to bring down operating costs while still meeting the clients’ requirements for better irrigation coverage area and acceptable pressure levels.
Contact us today (send your enquiry or request for a brochure) and we’ll provide you with excellent recommendations tailored for your application. We have an experienced team of mechanical engineers, production and quality assurance managers & professional dewatering consultants who are always ready to answer your enquiries. We have local offices at NSW, Queensland and Western Australia.