In the article we will talk about 3-way valves with and without electric actuator. There are a large number of valves, but it is precisely such devices that are rarely used. The design is somewhat reminiscent of a tee, but only the function of the device is different. Why do we need a valve of this design and how does it work? Let's try to answer these difficult questions.
How does the valve work?
A valve is installed in sections of the line where it is necessary to separate the fluid flow into circuits with a constant and variable hydraulic mode. It often happens that a constant flow is necessary when high-quality liquid is supplied in strictly defined volumes. A variable flow is used, as a rule, at those facilities where the quality of the liquid does not play a big role. More attention is paid to the quality factor.
Please note that two-way valves are also stop valves. But the difference from the 3-way valve is that the principle of operation is somewhat different. The design has a rod that does not block the flow of coolant with constant hydraulic performance. It turns out that he is constantly in the open position, tuned to a certain amount of coolant. Using the device, you can adjust the required volume of coolant both in terms of quality and quantity.
Mixing devices
Devices can be divided into two large subgroups:
- Mixing.
- Separating.
Features of functioning can be seen from the names. Mixer has one input and two outputs. In other words, with the help of such devices, two flows of the coolant are mixed. This is usually necessary for cases when it is required to lower the temperature of the liquid. Typically, such designs are used in the implementation of temperature control of a warm floor.
The adjustment process is simple, it is enough to know the temperature indicators of the flows that enter the valve. It remains only to calculate the proportion, and this is a school course in mathematics. By the way, if the installation and adjustment are carried out correctly, then it can be done so that the device can easily separate the streams.
Isolation valves
As for the second type of valves, they are able to split one stream into two. His design provides for the presence of one input and two outputs. The device is used, as a rule, if it is necessary to carry out the separation of the flow of hot liquid in the DHW system. Often it can be found in the piping of air heaters.
Design Features
Structurally, both types of valves are similar. But if you look at the drawing, which is given in our article, then the differences are immediately evident. In the mixing valve, a rod with one ball valve is installed. It is located in the center and closes the main passage. In the separation devices, the stem has two of the same valve, they are installed in the outlet openings.
The work is as follows:
- One of the valves is pressed against the seat and closes the passage.
- The second valve, on the contrary, opens the passage.
There are manual and electrical devices. This is one of the options for classifying devices.
Manual and electric
Most often, hand-operated devices are used, outwardly they are similar to simple ball valves. Here are just three output branch pipes for connection to highways. Electric devices have fully automatic control, usually they are used in private homes. Moreover, such devices allow heat to be distributed as evenly as possible. And the control system allows you to set your microclimate in separate rooms. Quite often, such devices are mounted for the functioning of the underfloor heating system.
When installing a 3-way valve with an electric actuator, it is necessary to take into account the pressure in the system and the diameter of the lines. These parameters should be fully consistent.
Buying a valve: what's important?
Manual flow control is performed using simple ball valves. Appearance such as that of a conventional valve. But there is an “extra” way out. Such fittings are used to carry out forced manual control.
Automatic devices are equipped with an electric motor or relay. They allow you to change the position of the stem. This actuator is connected to a thermostat so that temperature can be adjusted in the line. When buying a 3-way valve with an actuator, you need to pay attention to such points:
- Diameter of branch pipes for connection to a heating highway. Typically, the values are in the range of 20..40 mm. But it all depends on the specific highway and its features. In the event that it is not possible to find suitable diameter devices, you can mount adapters.
- Is it possible to install a servo on the device. After all, if there is such an opportunity, then the manual valve can be easily turned into an automatic valve.
- What is the throughput of the highway.
Installation of mixing devices
The scheme is used, as a rule, in boiler rooms connected to hydraulic separators or pressureless collectors. The circulation of the coolant in this case is due to the operation of the pump. If the valve is connected directly to the heat source on the bypass, then you need to connect a device with hydraulic resistance, like a boiler. In that case, if you do not take into account this nuance, the flow rate will fluctuate over a wide range.
It is not recommended to install the 3-way mixing valve to the pressure manifold or heating systems. But only if there are no devices that throttle excessive pressure. Otherwise, significant fluctuations in fluid flow will be observed. In order to get rid of excessive pressure, it is allowed to install a jumper parallel to the valve mix.
Features of mounting the separation valve
The installation diagram is given in the article. The main objective of this device is to perform a quantitative adjustment by changing the cost of the coolant. Previously, we examined the principle of operation of such devices, so we will not mention them anymore. Installation should be made in places where heat transfer to the return line is possible. In this case, it is not allowed to stop circulation.
Please note that the losses at the bypass balancing valve and the consumer must be equal. This will allow to link hydrocontours. The pressure in the system is created due to the operation of the pump. Installation of a 3-way control valve allows you to distribute the flow of fluid under pressure in two lines. But it is possible to realize this exclusively in systems in which constantly high pressure. That is, subject to the availability of a pump.