Electromagnetic solenoid valve for used water

When you hear “solenoid valve for water used”, many people immediately think of cheap China or dubious supplies. But in reality, this is often overlooked - second-hand versions can be rebuilt with replacement of seals and coils, and last for years if the supplier does not cut corners. I myself encountered that new valves from the mass market failed faster than these “used” ones with the correct revision.

What is behind the term 'boo' in the context of solenoid valves?

Boo is not always dirty parts from a showdown. In our practice, through Shandong Linyao Intelligent Agriculture Technology LLC, we took a batch of such valves for tests on drip irrigation. It turned out that some of them were illiquid goods from European production facilities, where the standards were simply changed and the equipment was stored in warehouses. The coils are 220V, brass bodies - it seems like a small thing, but after replacing the seals they worked like new.

The key is to check the solenoid for overheating. Once I came across where the coil was rewound at home, and on the third day of work the insulation began to melt. I had to open it up and look at the wire markings. Now I always test on a bench for at least 72 hours before installing it in the system.

Another nuance is compatibility with pulse control units. Some boo-valves, especially older Danfoss series, may not respond adequately to short pulses. I check the response time with an oscilloscope - if it’s more than 20 ms, I’m already at risk of using it only on a line with a soft start.

Experience in integration into smart agriculture systems

In projects for Shandong Lingyao, we used such valves in remote irrigation control schemes. I won’t say that everything is smooth - there was a story when three valves from a batch of 50 pieces failed at the first frost of -5°C. We took them apart and it turned out that there was water left in the chamber, and the seals were not frost-resistant. Now before winter storage I make sure to blow it with air.

An interesting case was with fine filters - when they installed boo-valves at the entrance to the fertigation system, one began to leak after a week. The reason is a fine abrasive suspension in the water, which killed the Teflon seal. We switched to ceramic valves, although they are more expensive, but the service life is higher.

With automation it is more difficult - some old solenoid valves do not work well with frequency regulators from the same manufacturer. I noticed that units with copper windings work better than aluminum ones - they heat up less during long-term operation at partial opening.

Typical mistakes during selection and installation

The most common thing is to ignore the pressure in the system. Once we installed a 6 bar valve in a system with 8 bars - after a month the solenoid began to hum, and after two months it jammed in the half-open position. Now I always measure peak values ​​with a pressure gauge before installation.

Another point with connection is phasing. Once they mixed up zero and phase on a three-phase switchboard, the valve worked, but the coil burned out within a week. I had to explain to the customer why the current protection did not work.

Installation in the field is a different story - if you install it in front of the valve without a mud trap, any sand will damage the plunger within a month. Now I always complete with coarse filters, even if the customer saves.

Comparison with new analogues in real projects

Last year we compared used valves and new ones from a Turkish manufacturer in a greenhouse complex. The new ones worked more stably during voltage surges, but the used versions turned out to be more repairable - in the event of a breakdown, only the coil was replaced, and not the entire assembly.

I noticed an interesting pattern - European boo-valves of the 90s often have a reserve of copper in the winding. Modern analogues are thinner and save on material. I checked the no-load current - the old samples are 15-20% lower, which means less heating.

The situation with water hammer is ambiguous - new valves with soft start are better, but if the system has a receiver, then the bu-variants can cope. The main thing is to correctly calculate the closing time.

Prospects for use in modern agricultural complexes

Now in Shandong Lingyao we are testing a hybrid scheme - new valves on the main line, used ones on the branches. Savings of up to 40% without loss of reliability, but more frequent condition monitoring is required.

I noticed a trend - modern systems with IoT sensors work better with valves that have position feedback. Such functionality is rarely found in used versions; it has to be modified with limit switches.

It’s interesting with energy consumption - some rebuilt valves consume less than new similar models. Apparently due to manual adjustment of the core during repair. I measured it - the difference is up to 3-5 W per valve, which is significant for large farms.

Recommendations for maintenance and service life extension

Once a season, be sure to disassemble and check the elastomers. If you use hard water, more often, every 2-3 months. I noticed that silicone seals last longer than rubber ones in conditions with pH changes.

It’s easier with coils - I check the insulation resistance with a megger. If it is below 5 MOhm, it is better to replace it immediately, otherwise the very first voltage surge will kill the solenoid.

Installation tip - I never install it without a drainage hole at the bottom point. Even if the valve is specified as waterproof. Condensation still accumulates, especially in underground wells.