Three way ball valve

To be honest, I still meet designers who are sure that a three-way valve is just two two-way valves in one body. It’s hard to explain that there is a fundamentally different mechanics for redistributing flows. Last month, just at the facility of Shandong Linyao Intelligent Agriculture Technology LLC, it was necessary to urgently change the configuration of the unit - someone installed a three-way ball with the wrong deflection angle, as a result, the flanges almost came off during a test run.

Design features that you won’t see in catalogs

Now many manufacturers are rivetingthree way ball valveswith identical flow sections on all nozzles. But for drip irrigation systems, for example in Shandong Lingyao projects, an asymmetrical option is often needed - where the side outlet is 20% narrower than the main channel. This is rarely written about in technical descriptions; you have to negotiate with the plant yourself.

I noticed an interesting detail: in full bore valves, the brass ball often has microscopic cavities on the surface. It would seem like a trifle - but it is these irregularities that become centers of crystallization of salts when working with hard water. After a season, such a ball begins to wedge, especially at the 45 degree position.

Speaking of materials, models with Teflon seals are absolutely not suitable for our northern regions. At -25°C, Teflon hardens and the valve stops holding. At one of the greenhouse complexes we had to switch to reinforced fluoroplastic, although initially the estimate was increased by 15%.

Installation nuances that the instructions are silent about

Never mountthree way ball valvewith drive without additional support! I once saw how an electric drive at a pumping station was unscrewed due to vibration within a day - the design turned out to be too lever-like. Now I always install either a bracket or at least a rigid liner on both sides.

Another point is the direction of flows. Some installers still confuse which pipe is considered the inlet pipe. But in the same catalog https://www.lyzhihuinongye.ru it is clearly shown that their models have an L-shaped stroke from the central port to the side. A trifle, but it saved me a week of debug on starting the fertigation system.

When tightening flange connections, be sure to leave a gap of 1-2 mm between the sealing surfaces. Otherwise, thermal expansion creates bending moments that deform the body. Tested by bitter experience - after a winter start-up, three valves leaked along the parting line.

Real cases from the practice of Shandong Lingyao

Last season, on a smart greenhouse project near Voronezh, we encountered abnormal wear on the ball surfaces. It turned out that the fertilizer manufacturer changed the recipe - they added ammonium nitrate with a higher content of chlorides. We had to urgently switch to ceramic-coated valves, although their cost was 2.3 times higher.

I remember an incident on a cascade filtration system - therethree way ball valvewith an electric drive had to switch flows every 12 minutes. After two months of operation, problems began. They disassembled it - and there sand with a fraction of less than 50 microns was packed in the cavities. I had to install an additional cyclone separator in front of the valve group.

By the way, Shandong Lingyao has interesting know-how - they integrate pressure sensors directly into the valve body. Not the most elegant solution from a hydraulic point of view, but it greatly simplifies diagnostics. Particularly useful for remote sites where there is no permanent technical staff.

Typical selection mistakes and how to avoid them

The most common mistake is choosing a valve based only on the connection diameter. I recently saw a project where an engineer took DN50 for a 2.5 atmosphere pipeline, and the operating pressure in the system was 8 bar. Naturally, a month later leaks appeared along the rod.

Don't forget about the response speed! For automatic irrigation systems, sometimes it is not so much the characteristics of the valve that are critical, but rather the switching time. Once I had to replace half a batch of electric drives - they worked in 12 seconds, and the technological process required no more than 5.

Pay attention to the type of drive connection - many Chinese manufacturers have non-standard connectors. We are now mainly working with products from Shandong Lingyao; they at least have a unified Modbus RTU interface. Although last year they also had a batch with mixed up contacts...

Promising developments and personal observations

Lately I’ve been looking at hybrid solutions - wherethree way ball valveand a check valve. A very promising design for pumping stations, but so far I have only seen experimental samples. In Shandong Lingyao they said that they would launch mass production by the end of the year.

I noticed a trend towards increasing service life - modern models can already withstand up to 100 thousand switching cycles compared to 30-40 thousand five years ago. True, this is achieved due to harder seals, which requires an increase in torque on the drive.

I saw an interesting solution in their new catalog - valves with the ability to partially block flows. Previously, it was believed that ball mechanisms were not intended for regulation, but it turned out that with a certain channel geometry it is possible to achieve a fairly linear characteristic. We'll check it next season on a test plot.

Conclusions that you won't find in textbooks

Over 12 years of working with pipeline fittings, I realized the main thing - there are no universal solutions. Even the most expensivethree way ball valvemay turn out to be useless if the specifics of a particular technological chain are not taken into account. This is especially true for agricultural projects where operating conditions change seasonally.

Never skimp on shut-off valves - replacing them costs 3-4 times more than the initial savings. It is better to take a model with a pressure class higher than that provided for in the project. As practice shows, our technologists will always find a way to increase the pressure in the system 'temporarily'.

And most importantly, maintain relationships with manufacturers. The same specialists from Shandong Lingyao more than once helped out with non-standard solutions when it was necessary to adapt equipment to specific conditions. In our work, ready-made catalogs are only the starting point for dialogue.