For many countries in the world, agriculture is one of the most important components of the economy. The sector works both for the domestic market, providing citizens with products, and for exports. It is therefore not without reason that countries are divided into ‘agrarian’ and ‘industrial’ type.
The main production resource required for the life of any agricultural enterprise specializing in both animal husbandry, and crop production, is water. In order to distribute this and any other vital substances required to sustain life, hoses and pipes are needed.
By Jurij Artiukhov, General Manager, PipeTime, LLC
The harvest and quality of the crop, as well as the livelihoods of forage animals, depend on a land’s quality of irrigation and ability to achieve the required amount of moisture. The importance of ensuring that these needs are met has therefore led irrigation technology through a progressive history.
In the past, special aluminum pipes PMT (field main pipeline) were used for irrigating fields, see Image 1. PMT pipelines were made up of 6 m sections with special sockets at the ends that fastened together with a locking system. Although the cost of this irrigation solution was relatively low, when compared with more modern pipeline technologies, many companies began to think about the additional costs incurred by the PMT pipe. More specifically, they began to assess the logistic costs associated with this type of piping.
PMT pipelines have a weak link that is often subjected to loads due to soil movement or temperature changes. As a result, the connection will lose its tightness. While in cases of water distribution this is not a threat to the environment, when it comes to pumping manure, such breaks can cause financial and reputational losses.
It is due to the combination of reasons listed above that agricultural enterprises began to look for other technologies to meet their needs.
Rubber Irrigation Hoses
One solution to many of the major pain points associated with classic Russian pipelines is to use rubber irrigation hoses. Available in diameters that range from 10 mm to 150 mm, the working pressure of rubber irrigation hoses, as a rule, is not more than 10 atmospheres; it is important to note that the larger the diameter, the lower the working pressure. Rubber hoses also have specific length restrictions based on their diameter. A 100 mm hose, for example, has a continuous length of about 30 m to 40 m and can connected to another hose using Camlock connections, flange connections or BAUER connections, see Image 3.
If the project requires water to be transported several kilometers, then the laying of a rubber pipeline carries certain difficulties and risks. Since achieving such a long distance would require a number of hoses, and therefore a number of joints between the hoses, the risk of depressurization and further filling increases. In addition, many regions of agricultural activity have a significant amount of sunlight (ultraviolet radiation). As the rubber used for the production of irrigation hoses is not resistant to prolonged exposure to sunlight, after 6 to 7 months operation (in other words, one season), the rubber can crack and break down.
Of course, there are rubber water hoses with various polymer additives that make rubber UV-resistant, but the market has developed in such a way that not all agricultural companies can purchase such hoses.
The progressive nature of the hose industry has led many manufacturers to offer products made from polyvinyl chloride (PVC) to combat the challenges that arise with standard rubber hoses. PVC hoses, in their classical sense, are mainly used for irrigation in garden areas. They have a standard working pressure up to 2 to 3 bar, a continuous length up to 30 m, and diameters that range from 10 mm to 50 mm, see Image 4.
Unfortunately, these diameters do not provide sufficient water passage for fields that span several hectares. These types of hoses are more suitable for solving local problems, such as apple fields, where whole irrigation systems are formed from similar PVC hoses, interconnected by various plastic fittings.
PVC hoses are also used to introduce liquid manure (water) into the soil using sprinkler machines known as pivots. The liquid fraction passes through hoses to special aerator mixers, where the manure is saturated with oxygen; this is done in order to homogenize the manure and reduce the unpleasant odor. The manure is then moved along the main pipeline, either a PVC hose or a polyethylene pipe, to the sprinkler machines. The sprinklers then spray the liquid evenly into the soil, see Image 6.
PVC Flat Hoses
PVC flat-rolled hoses, which are made of the same polyvinyl chloride, have now become very active in the market as well. Unlike a classical PVC hose which can operate in both a pressure and section mode, flat-rolled hoses are not equipped with a spiral, which prevents them from working in a suction mode. The main advantage of PVC flat hoses is their continuous length, which can reach 100 m to 200 m. In fact, the extrusion process, which is used in the production of flat PVC hoses, allows for the fabrication of continuous lines up to 500 m and more; this length is, however, extremely inconvenient to use, see Image 5.
Discharge flat PVC hoses are used as main pipelines for the organization of drip irrigation (irrigation in the fields). The distinguishing features of discharge PVC hoses are the special holes in the body of the hose. Plastic plates with a nozzle, pressed from the inside and outside of the flat hose, make it possible to attach plastic pipes that carry out drip irrigation, Image 7.
Other advantages of PVC hoses are: the continuous length of the coil, ease of installation, and the variability of use. The main disadvantage of these hoses is that they are also exposed to ultraviolet radiation, which leads to their rapid deterioration and failure.
Thermoplastic Polyurethane Hoses
The most modern solution for irrigation of fields are flat-roll hoses based on thermoplastic polyurethane. As in the case of PVC, the most common lengths are 100 m and 200 m, with a range of diameters from 25 mm to 400 mm, and a working pressure that in a number of diameters can reach 63 bar. Thermoplastic polyurethane is a wear-resistant material, that is resistant to tearing, and most importantly, to ultraviolet light. Its operating temperature ranges from -60C˚ to + 80C˚ and it can be equipped with any type of connections, including special quick-release couplings.
Case Study – Benefit of Flat-Rolled Hose
A Russian agricultural company, located in the city of Krasnodar (one of the sunniest and driest regions of Russia, where the main agricultural lands are located), was tasked with ensuring the transportation of water 4.3 km from a reservoir to a field. The terrain was a hilly surface, which complicated the task, and the water intake point was only to be used for one season, then moved to another site.
The use of either PMT pipes or rubber hoses therefore entailed significant logistical and time costs. After deliberation, the agricultural company chose to use a 200 mm flat-rolled hose with a working pressure of 10 atmospheres; the hose was equipped with quick-release couplings for ease of installation. The laying, with the help of a special winding device and the forces of a team of four people, took 27 hours, see Image 8.
At first glance, it seemed that the purchase of an expensive polyurethane hose did not bring economic benefits, but considering all the costs of logistics, installation, as well as subsequent assembly, this solution turned out to be the most cost-effective. In addition, the service life of a flat polyurethane hose is 10 years or 3000 cycles (one cycle refers to the process of installation, work, dismantling). While polyurethane flat hoses are not currently a common solution for the agricultural market in Russia, it is a dominate solution for the US market. The largest market for any TPU flat hose plant is the US, which consists of roughly 60% to 80% of the plant’s turnover.
Hoses for Manure Dispersion
During the growing season (the period of plant growth and development), an important factor for successful crops is the timely and high-quality introduction of the manure fraction into the soil. Used for fertilizing and growing crops, a pumping station transports the manure through a main pipeline from a lagoon (manure storage). The main pipeline can be of a stationary design, or it can be flexible.
As the length of such a line can reach 5 km, the use of a flat polyurethane hose with a minimum number of connections is a justified solution. From the main pipeline to the tractor that sprinkles the manure, the so-called drawing or towing arm is used, see Image 9. As a rule, the maximum diameter of the towing hose is 125 mm to 150 mm, and quick-release locks are used as connections (since they can withstand a similar tensile load and not lose tightness).
The manure fraction is transported through the hose to the tractor, to which special nozzles inject manure into the fertilized soil. Such a mode of operation implies colossal loads on the hoses; namely the hose is afflicted with constant bends and twists, tensile forces (tractor power of about 300 horsepower), and contact with the surface (sand, stones). With the productivity of approximately 3000 m3 per shift, thermoplastic polyurethane has no competitive counterparts yet that can cope with this task. Manure contains dry fractions and particles, as well as traces of soil, small stones, etc., which imposes certain requirements on the wear resistance of the inner surface of the polyurethane hose.
Flat hoses made of polyurethane are successfully used on pig farms, where, often, lagoons are overflowing and it is necessary to pump fractions from one lagoon to another.
Hoses in agriculture are arteries, without which the existence and development of agricultural crops is impossible. With a number of innovative technologies prevalent in the industry, there is range of hoses offered on the market that are able to satisfy a company with any capital and size of business – from garden land to a multi-hectare field.
About the Author:
Jurij Artiukhov works as the General Manager at PipeTime, LLC. He previously worked as a Sales Manager for MTT Company and Project Manager for SOL SP Company. He holds a graduate degree from the University of Foreign Affairs, Economy and Law.