Solenoid valves

To be honest, I still come across projects where solenoid valves are treated like simple taps - turn it on and forget it. Especially in drip irrigation systems, where pressure surges and suspended matter in the water turn the electromagnetic mechanism into a headache after six months. We had a case in Shandong Linyao: the customer demanded to supplysolenoid valvesdirectly after the sand filter without a gearbox, arguing this with “savings on piping”. After two months, 40% of the valves had failed—not because of the coils, but because of plug erosion. I had to redo the circuit with intermediate diaphragm valves, but the lesson was remembered for a long time.

Structural subtleties that are not written in the specifications

Now I often take our projects from the website https://www.lyzhihuinongye.ru as examples - you can see there how the approach to valve selection has changed. Previously, they installed standard brass housings with 220V coils, until they encountered electrochemical corrosion in soils with a high salt index. As a result, for greenhouse complexes they switched to AISI 304 stainless steel, although initially it seemed that this was excessive for water.

Reels are a different story. Until now, some manufacturers save on winding by using aluminum instead of copper. In conditions of voltage surges in rural networks, this leads to overheating and interturn short circuits. We at Shandong Linyao Intelligent Agriculture Technology LLC now test each batch for heat resistance - not because technical regulations require it, but because we have gained bitter experience with replacing 200 coils per season.

It is interesting to observe the evolution of connections: if previously the G1/2 thread dominated, now for main lines we more often use DN50-DN80 flanges. This is not a tribute to fashion, but practice - when installing 40 mm HDPE pipes, the flange connection provides better tightness during vibrations. Although for side branches we still prefer threaded versions - maintainability is higher.

Real cases of integration into irrigation systems

Last year we did a project for a vegetable farm in the Rostov region - there it was necessary to manage the irrigation of 12 sections of 5 hectares each. We installed Danfoss EV220B valves, but with modifications: we added a manual override and a 100 micron mesh filter right in front of each valve. At first the installers were indignant at the “extra elements”, but after analyzing the water they agreed - the content of carbonate suspensions was critical.

The peculiarity of that project is the combination with our systemremote valve controlvia GSM modules. Here it was important to select valves with low energy consumption so that the batteries on the solar panels would not run out overnight. We had to abandon pulse models - despite the savings in standby mode, their inrush current created voltage sags.

The most difficult thing turned out to be not in technology, but in logistics - when 3 DN65 valves were required for urgent repairs, and only normally closed versions were available, while normally open ones were needed. We had to temporarily install bypass lines with ball valves while we were waiting for delivery. Now we always keep emergency kits of different types in stock.

Automation pitfalls

Many people forget thatsolenoid valvesThese are just actuators. Without proper wiring and a controller, they work at half capacity. We had a precedent in the Krasnodar region, where a customer bought expensive ASCO valves, but connected them through simple time relays. The result was water hammer when 8 valves were started at the same time; the entire cycle had to be reprogrammed with interval activation.

Now, when designing automatic irrigation systems, we always include a soft start through our own-produced frequency converters. This increases the cost of the project by 15-20%, but increases the service life of the valves by 2-3 times. By the way, for small farms we sometimes recommend a hybrid solution -solenoid valvesonly on the main line, and on the side lines there are membrane ones with electric drive.

An interesting point with flow sensors is that their absence often leads to idle operation of the valves when the pipeline breaks. In Shandong Lingyao, after the greenhouse flooding incident, we now always install at least the simplest flow relay. Yes, these are additional costs, but they are paid off by preserving the harvest.

Specifics of installation and maintenance

When installing in the field, the need for drainage wells is often overlooked. The standard advice - to install the valve above the pipeline level - is not always feasible in flat areas. For such cases, we have developed compact caissons with a drainage system that protect against flooding with groundwater.

Maintenance is a separate headache. The instructions say “clean once a season,” but in reality, with hard water, you have to disassemble it every month. Our technicians have adapted to using citric acid to remove scale instead of chemical reagents - less harm to the seals.

Spare parts are an eternal problem. For European brands like Burkert or SMC, delivery of gaskets or springs takes 4-6 weeks. Therefore, we now complete objects with repair kits right away, even if the customer considers this unnecessary. Practice shows that this saves up to 70% of time for repairs during peak season.

Economy vs reliability

I still encounter the myth that the Chinesesolenoid valves- this is guaranteed to be of low quality. After testing 12 brands, I can say: there is a difference between top-end and budget models, but it is not always critical. For example, for seasonal greenhouses with low intensity of use, valves in the mid-price segment are quite suitable.

On the other hand, for perennial crops such as vineyards, where failure of irrigation means the loss of a year, it is better not to save. In such cases, we recommend valves with redundant coils - yes, they are 40% more expensive, but the failure of one coil does not stop watering.

An interesting trend in recent years is the transition to low-voltage valves (12-24V) even for industrial facilities. At first I was skeptical, but after calculating the losses in long cable runs I realized the advantage. Especially for Shandong Linyao Intelligent Agriculture Technology LLC facilities with distributed fields up to 2 km.

Perspectives and personal observations

We are currently testing valves with an IoT module for our “smart fields” projects. - interesting, but so far the stability of the connection leaves much to be desired. Apparently, we will have to wait for the development of 5G networks in rural areas.

One of the less obvious problems is that birds often peck at cable couplings on field valves. It was necessary to develop protective covers made of polycarbonate, although initially it seemed that this was an excessive measure.

The main conclusion from 10 years of work: there are no universal solutions. What works perfectly in a greenhouse complex near Moscow can completely fail in the Stavropol steppes. Therefore, now every project of Shandong Lingyao LLC begins with an analysis of water and soil - it seems like a trifle, but these are the “little things” determine the success of the entire irrigation system.