Among drip irrigation products, regardless of it comes to residential or agricultural systems, you may need to use different types of drippers. The different drippers offered in the SAB range can be fixed with a different delivery capacity ranging from 2l/h to 16l/h; or adjustable with a delivery capacity ranging from 0-40 to 0-60l/h, allowing the most suitable drip micro-irrigation, based on the various plant needs and soil nature.
Among the various types of drippers, we may find:
Rambo dripper
This dripper has a tablet with a labyrinth for water passage inside it. Its tablets are of different colors and each color refers to a specific flow rate of the dripper. The base is made of UV-resistant polypropylene that resists both weathering and possible corrosion typical of fertirrigation. It allows a fast cleaning, as it can be easily taken apart. It may be used for water that is not much filtered and for plain terrain where pressure compensating drippers are not necessary. It is suitable for irrigations systems such as vineyards, orchards and olive groves.
PC Rambo dripper
This dripper is able to maintain a constant flow rate, allowing a homogeneous and correct water distribution, even in case of sloping systems or long lines. It is as easy to disassemble as the Rambo dripper, so it ensures a fast cleaning, if needed, and it is still composed by a propylene anti-UV base. It is suitable for drip irrigation systems for greenhouses, nurseries, orchards, vegetable gardens and vases. You can insert it in the capillary tube or directly in the main tube, through the use of a hollow punch.
Sting dripper
This model of dripper is compact and consists only of a single not inspectable piece. It is very easy to install; indeed, it is self-perforating, which means that its emitter can be directly installed on the tube, without having to perforate it earlier. It is a self-compensating dripper, and therefore it is capable to maintain a constant flow rate; this feature makes the dripper definitely very suitable for applications in steep lands, unlike standard drippers, which prefer flat lands. Sting drippers are recognizable for their color, too, that differs based on the flow rate to supply.
Minidelta dripper
It is cigar-shaped and, like the above-mentioned drippers, it is inspectable and can be removed thanks to its components with extreme ease, allowing a cleaning for any clogging. Minidelta can be installed on the tube the same as standard drippers; plus, it features a hook that permits you to fit it to the pipe with a double support for the dripper. This reduces the chance of detaching from the pipe and of fall. The dripper contains a labyrinth that helps water to flow and it is particularly suitable for orchards.
Adjustable dripper
It ensures a 360° rotation with an 8-jets irrigation. It is regarded as adjustable because you only have to strengthen the dripper head to adjust its flow rate. It is also inspectable and, thus, removable; by fully unscrewing its head, you can have an easy cleaning and maintenance, if necessary. It is suitable for drip irrigation systems, on drip lines of 16mm or 20mm and also for plant and vase irrigation.
What are the tests to analyze the proper functioning of drippers?
The tests carried out comply with the norm ISO 9261 and are also used to test drip tapes.
First of all, you need to distinguish between Online emitters and Inline emitters. The above-mentioned drippers are online emitters, as they are installed on the tubes, whereas inline emitters are pre-inserted along the tube length during the extrusion process at fixed intervals, resulting for example in our Alis drip line. With this respect, the tests carried out on drippers are very similar to those carried out on drip tapes.
Indeed, one of the main tests is the uniform flow rate, that is the calculation of the flow rate coefficient of variation (CV).This test considers 10 drippers on a special test machine; you have a pressure equal to the nominal pressure, that is 0.7 bar. The flow rate is detected for each dripper, then you take the average of the flow rate of all drippers and, by applying a particular formula, you obtain the CV. The flow rate average shall not be different from the one declared of +-7%, whereas the value of the CV shall be lower than 7%. This is one of the most important parameters which determines the dripper accuracy.
The second test is the continuation of the previous one, and it assesses the flow rate variation according to pressure.You increase the pressure step by step, and maintain it for 3 mins, at each pressure step you calculate the average flow rate and assess how much it varies compared to the one declared in the catalogue and it must not vary by +-7%.This test provides the well-known curve, the average flow rate values at the different pressures and you obtain a curve. The more the curve tends to be a straight line parallel to the horizontal axis, the more the dripper performance is optimal. Indeed, the curve of the self-compensating drippers is almost flat, as you see in the graph.
Thus continuing, you may also verify that the dripper does not escape from the tube so that the mechanical joining works. Therefore, you apply a force to the tube for a set period of time, after which the dripper must not break off.
Finally, the last test covers the water tightness of the tube-dripper joining. Indeed, once you have installed 5 drippers on the tube, the pressure is applied and increased step by step; indeed, any water leakage in the connection between the tube and the dripper should not happen.
