Solenoid valve. Everything you need to know about the water supply valve Make a normally open valve yourself

Not a single modern pipeline can operate without valves, regardless of what exactly is being transported through it. These devices perform several functions at once, among which we can note protection against water hammer of sensitive equipment (pumps), regulation of pressure in the system, etc. What speaks in their favor is that the installation of such a device is extremely simple.

Valves classification

Similar devices on water pipelines (as well as gas pipelines, etc.) are used for several purposes:

• protection of equipment from pressure surges– for example, check valves are usually installed in front of pumps to prevent damage to the equipment during water hammer. The installation is carried out using detachable connections, so even if you have no experience, you can do the work yourself;

• adjustment function– water pipes are only allowed in one direction, so it will help in this situation too. As soon as the water tries to head towards reverse side, the petal will block the passage in the pipe;

• valves can also be used to regulate the pressure in the system, the boundary force is selected at which the transported medium opens the valve, as a result, as soon as the pressure in the pipeline exceeds the maximum, it will open and the pressure will equalize. Air valve on a gas pipeline - an irreplaceable thing.

This does not exhaust the functionality of shut-off and control devices; they can also be used to control pumps and when cleaning Wastewater, to minimize leaks, etc.

Read more about the design and principle of operation of different types of valves

Recently, in addition to conventional valves (which operate solely on the basis of the application of force), electromagnetic analogues have also appeared; they can be controlled remotely. A water solenoid valve can be used, for example, in a system " smart House", from one remote control you can control control devices throughout the house and in the surrounding area.

Solenoid valves

The key difference from other analogues is that it does not allow water to pass through when pressure increases, but solely at the command of a person. This is their main advantage.

As for the design, the key element can be considered the coil, which, when passing through it electric current causes the core to move, which opens/closes the passage hole. Such devices can operate either from batteries (supply voltage 24V) or connected to the network (voltage 110V or 220V).

As for classification, we can distinguish:

• normally open/closed or bistable;
• Also, a 220 V solenoid water valve can perform: flow switching function (2/3 way), shut-off (2/2), three way (3/2).

Note!
When choosing, you need to take into account the operating features of each model.
For example, if an electromagnetic shut-off device is produced with servo control, then you need to know that it simply will not work at zero pressure drop, so at least a minimum pressure drop is still needed.

Regarding the field of application, electromagnetic devices fit perfectly into the concept of “ smart home" For example, an electric water valve installed in a caisson will be able to drain automatically, without even having to leave the house, and this example is the simplest.

Simple and combined models

When operating a water pipeline, you have to solve problems such as:

• releasing air pockets from pipes that formed directly during operation;

Note!
This problem especially often has to be solved when operating a heating system.
All radiators require the installation of a special valve to release excess air.

• when draining water (for example, while preserving a pipe for the winter), it is necessary to ensure an air flow that replaces the drained water in the pipe;
• When the pipe is filled, the valve must allow air to escape.

A simple Mayevsky crane with manual control, the price of such a device does not even reach 200 rubles.

But other types of shut-off and control valves can also be used:

• for automatic bleeding overpressure single-function valves are used. They are used to maintain the functionality of pumping equipment, etc., except for equalizing the pressure in the system; it is not suitable for anything else;
• combined - allow you to solve all the listed problems. Their device uses a movable float; when the pipeline is filled with water, it rises and blocks large holes through which air enters; when water is drained, it also falls, the holes open and a vacuum is not created in the pipe.

Note!
also in combined devices There may also be small holes to equalize pressure.

Drainage

A drain valve can be used not only in a house to discharge water from pipes, but also as a device to ensure the safety of water supply from a well. Such devices are similar in principle to combined air devices and in winter, when the pressure in the pipe decreases, they discharge water into the well.

When the pressure is above the minimum, the ball closes the outlet and the water is flowing to the house. If the pressure drops below the minimum mark, the ball opens the outlet and water flows back into the well, this allows you to preserve the system when the water in the pipe freezes.

A drain valve is useful for protecting hoses and pipes of an irrigation system; such a device is especially useful when laying a separate water supply for irrigation. If the pipe is not laid very deep and there is a risk of freezing, then the drainage pipes themselves will discharge the remaining water from the system.

Of course, you can just install a drain valve and do the same yourself, but perfect memory no one can boast. The valve will definitely not forget to drain the water.

As for installation, a threaded (that is, detachable) connection is most often used. Most often, the entire instruction is to tighten union nut hands, and then tighten it with a key. In industry, welded and flanged connections can be used.

Summarizing

The normal functioning of a water supply system without valves is simply impossible. It is this device that will allow you to drain water from the system and fill it again without any problems. air jams neither will it. The ease of installation of such devices only adds to their popularity.

The video in this article shows the installation of a check valve in a hot water supply pipeline.

The main thing in gardening is to ensure regular watering of the site. Without it, any garden will not survive even one season. Watering by hand requires a lot of time and labor. For nice garden needed modern system water supply, where important element is a solenoid valve for irrigation.

Advantages of automatic watering

The main elements of the irrigation system are as follows:

• water flow dosing;
• uniformity of application;
• efficiency (watering at night reduces moisture evaporation);
• the system is underground;
• saves labor and time for the gardener.

Purpose of the solenoid valve

An electromagnetic valve for irrigation is always needed, even if there is no irrigation system. It is used in conjunction with a timer that turns it on right time. It is especially needed to fill storage tank. When water is supplied according to the schedule, the timer opens the valve and the tank is filled. It is advisable to water the area at the same time. All this is done in the absence of the owner. All he has to do is water hard-to-reach places.

The main purpose of the valve is to supply water to the irrigation system at a given time. A 1-inch device is suitable for this, flowing 50-100 l/min at a pressure of up to 10 atm. It can also be used for short irrigation areas, as it allows you to adjust the required local flow rate. It is suitable for spray and drip irrigation when the pressure in the system is low.

One or more valves are installed on a drainage pad made of crushed stone and closed with a box. This can be done in any convenient place.

Solenoid valve device

The valve is very simple. It contains the following details.

The external thread of the inlet and outlet pipes is 1/4" or more depending on the fluid flow. The least amount of water passes through the solenoid valve for drip irrigation. Small-sized devices are built into a water pipeline and operate on a timer that sets different irrigation modes.

Recently, models combined with a switch have appeared. You can purchase through the Yulmart online store: the solenoid valve for irrigation C 1060 plus GARDENA, which has become popular. It automatically switches the water supply to irrigate the garden.

Solenoid valve for irrigation: operation diagram

Connecting a solenoid valve to a garden watering system

For a small garden would be better suited solenoid valve for irrigation -12 volts (NT8048). It is safe because if water gets on the contacts and touches wet hands no electric shock will occur. Possibility of connecting it to battery at 15 AH allows you to work without recharging for a week. It will also be easy to supply power from the shield via an AC adapter.

The water supply is provided from a storage tank installed at a height of at least 2 m. Water is drawn into it from centralized system. Filling is controlled float sensor connected to a plug valve. The absence of a pump eliminates many problems. Watering the garden by gravity occurs within a few hours and does not need to be controlled. All irrigation control will be taken over by an electronic timer connected to the outlet.

The valve is installed in the pressure line of the irrigation system. The electromagnet coil is connected to the output of the adapter via a cable using terminals. They can be sealed on top with sealant to protect them from water.

The entire device can be conveniently placed in a utility room where you can install an outlet. A timer, adapter and electromagnet coil are connected in series to it. All that remains is to configure the watering mode. The time is chosen in the morning and evening so that there is a minimum of evaporation and the plants do not get sunburned. The duration of watering is set, which is then selected experimentally.

On different types Plant watering should be different. The system can be gradually improved by adding new valves. You can connect your own timer to each of them or install a common microcontroller, setting the irrigation program.

Valves from old washing machines can be installed on the outlet pipelines, which will allow you to save a lot on the cost of the irrigation system.

Do-it-yourself solenoid valve for watering

Electric valves are expensive, but cheaper solutions can be found. The most accessible one here is a valve from a broken washing machine. Its structure is as follows:

• plastic case;
• rubber membrane;
• electromagnet with core;
• spring;
• mesh filter;
• pad.

The mechanism is highly sensitive to dirt and can easily fail. It is protected, but for a garden system it is advisable to install another one at the valve inlet, since the own one will quickly clog.

The solenoid valve is normally closed, i.e. when turned off, it shuts off the water. When turned on, the core retracts, raising the rubber membrane, and allows water to pass through.

Used to remove contaminated washing liquid. drain valve, arranged similarly. Its operating principle is the same and it can be successfully used for irrigation.

Solenoid valves of washing machines have the following characteristics:

• supply voltage - ;
• power - 8 W;
• water pressure - up to 10 atm;
• inlet hose diameter - 3/4";
• fluid flow - 10 l/min.

Malfunctions and repairs

Conclusion

Maintaining a garden takes a lot of time and effort. A real savior for the owner is an electromagnetic valve for irrigation, which serves to fill the storage tank in its absence, pump water from the well and especially in the irrigation system.

When developing my heating system, along with natural circulation, I planned to make myself a forced one so that I could attach an automatic regulator to it. After all, what does natural mean: you open it manually the right tap(or taps), and the heated water itself rises to the radiators, giving off heat there and then falling down to the heater (or to the storage tank, thermal accumulator). Thus, it is necessary to constantly monitor the temperature in the house in order to turn off the circulation in time, and then, when necessary, reopen it.

Well, it's inconvenient! I didn’t open it on time - it got cold in the house. Didn't close it - it's too warm, or even too hot. Not only is it uncomfortable, but there is also overspending when it’s hot. And overconsumption not only means that the stored heat is unnecessarily consumed into the house, but also the heat loss of the house increases, since as the temperature in the house increases, heat loss through the enclosing structures (walls, ceilings...) also increases.

This means we need automation. At first glance, there are no difficulties. A temperature sensor controls, say, a solenoid valve. The temperature in the house dropped - the sensor opened the valve. Increased - the valve closes.

I don't seem to have any problems with the temperature sensor. There is one. But the solenoid valve... I searched the Internet, looked at the price lists of online and non-online stores - expensive, damn it! And why would it cost that kind of money? I went to the metal market, talked to people, and got advice. Taking something cheap for 2-3 thousand rubles means taking a disposable item. But I don’t have a water supply system, I have heating! If something broke on the water, turn off the water and patch it up, but in the winter, if something happens, there’s no fuss about the heating - you have to drain the water, and do it quickly so as not to freeze... In general, the cheap thing doesn’t suit me, but the expensive valve , for 6-7 thousand rubles... And the wife, to put it mildly, persistently objects to such an acquisition.

But I still want automation. In Rus' they say: the need for invention is cunning. And I also decided to dodge and make it automatic, but at the same time not to upset my beloved and do without an expensive valve. Instead, I installed, you won’t believe it, a check valve. It costs literally a penny, and at the same time perfectly performs the functions of an automatic solenoid valve, however, only in conjunction with a circulation pump. You already guessed what it's all about, right? Yes, yes, that’s exactly the point: there is a spring in the check valve that presses the rubber gasket against the seat. This spring does not allow water to move in a forward direction during natural circulation, since the pressure is not so great as to press the elastic from the seat. But when the pump turns on and starts working, everything is fine, then the pressure increases, the spring compresses, and water flows freely through the valve and pump.

Hurray, hurray, and we throw our caps into the air. But there is one thing that should be taken into account. The strength of this spring was not calculated by the engineers for such an application, especially in my heating system. The trouble is that the pressure on it during natural circulation directly depends on the height of the water column, that is, on the distance at which the top point of the top battery is located in relation to this spring. To be fair, it is worth mentioning the dependence on the temperature difference above and below.

So, in my system this spring still lets through a little bit. That is, there is no complete closure when the pump is turned off. Therefore, I simply had to, without further ado, disassemble the valve and stretch the spring. The video shows this barbaric operation in detail. And only after this “modernization” was it possible to achieve normal operation automation. That is, when I turn on the pump, water flows, when I turn it off, the water does not circulate. Now you can throw caps with good reason.

I will answer any questions you may have about photography right away. Check valve in series with the upper pump - this is the valve we are talking about. The lower pump is another branch in the heating, which is still waiting for its modernization. But the upper pump with the valve, as can be seen in the photo, is bridged with a straight section of pipe with a tap. What is this for?

Any electric car works thanks to the presence of many special parts. We propose to consider what a normally closed solenoid valve is, its operating principle and where to buy it.

General information

Electromagnetic solenoid water or gas valve is an electromechanical device designed to control the flow of liquid or gas in devices with power up to v308 (EV220B, Tecofi, Castel, ESM, EVR, GBP, GBV, NBR, PARKER, SCE, SYDZ, AKPP, KSVM, ZSK, ISP, Burkert, KSP). This valve is controlled by an electric current passed through a coil. When current is applied, a magnetic field is created and causes the piston inside the coil to move. Depending on the design, the piston will open when electricity is supplied, or the bypass valve will close. When the current stops flowing to the valve coil, it will return to its normal state.

There are mechanisms:

• direct and indirect type of action;
• vacuum, hydraulic, pneumatic valve;
• 2-, 3-, multi-way.

Direct acting electric valves open and close an opening inside the valve. In experimentally controlled valves (they are also called a shut-off device), a piston opens and closes the hole. In valves high pressure(for example, a flanged valve) uses pistons and special seals that control the condition of the hole.

Video: Danfoss solenoid valves

Description of the design of the standard device

The simplest solenoid valve has two ports: one inlet and one outlet. Additionally there may be three or more ports.

Water or gas enters through the inlet (2). Any substance must pass through the tank opening (9) before entering the outlet (3). The outlet hole is closed by a piston (7).

The solenoid valve in the photo above is a normally closed solenoid valve of the ASCO, TORK or Danfoss type. It works as follows: these devices are connected to a spring (8), which presses on the piston against the opening of the flow area. The sealing material at the tip of the piston contains protection (gasket) against water or gas entering the holes while the piston is lifted by the electromagnetic field generated by the coil. The diagram demonstrates the operation of the standard one.

There are many variations in valve design. Conventional valves may have many ports and pistons. The two-way indirect-acting valve (return) has 2 ports - EV1140, DU50, DU32, DU100, DU15, DU25, RU16 series; if the valve is open, two ports are connected and fluid moves between them; if the valve is closed, the ports are insulated. If the valve is open, then the solenoid is not energized, then the valve is called normally open (NO). Similarly, if the valve is closed, then the solenoid is not energized, such a valve is called normally closed, say YCD21, YCPS31, YCWS1. There are also three ports and more complex structures devices, their designation looks like 30 (3, 33, etc.). The three-way valve has 3 ports to control the electric actuator; it connects one port, or two of them (usually the intake port and the exhaust port).

A small solenoid valve can produce limited force. The approximate relationship between the required electromagnetic forces Fs, fluid pressure P and orifice area A for a direct acting valve is:

Fs = P*A = P*pi *d 2 / 4

Where d is the diameter of the hole.

In some solenoid valves, electromagnetic forces act directly on the main valve. Others use small, full solenoid valves, known as manned. Piloted valves require much less power, but are much slower. These solenoids typically require full power at all times to open fully and hold that position.

Piloted Valve Design and Purpose

Gas shut-off pilot valve SCE238A002 (200 bar), NEMEN, VIKING, SPOOL, JOUCOMATIC, EVEN, SMART TORK, consists of two main parts: a bypass device and a direct-acting valve. The passage mechanism converts electrical energy into mechanical energy, which, in turn, opens or closes the part. A direct acting valve controls the flow of liquid or gas.

Solenoid valves may use metal seals or rubber seals, it is also easy to control. The spring is used to keep the valve normally open or closed when not in use.

Water under pressure enters the chamber. The inlet hole is an elastic membrane, and above it there is a spring that pushes it down. The diaphragm has a hole passing through the center, it allows you to control the amount of water, often a very small part is allowed through. This water fills the cavities on the other side of the diaphragm so that the pressure is equal on both sides of the valve.

After the diaphragm is closed by the valve, the bottom outlet pressure decreases and more pressure keeps the valve closed. Thus, the spring has nothing to do with closing or opening the valve.

If current passes through the diaphragm solenoid, the water in the chamber flows out through the straight passage faster than the chamber is refilled. Incoming pressure lifts the diaphragm.

When the solenoid is turned off again, the passage is closed by the spring, it takes very little force to push the diaphragm down, the main valve closes again. In practice, a separate spring is often missing; The diaphragm elastomer is adapted so that it operates as its own source, mainly in a closed form.

From the explanation it is clear that this type of valve depends on the pressure difference between the inlet and outlet, since for it to work the inlet pressure must always be greater than the outlet pressure. If the outlet pressure, for any reason, is higher than the inlet pressure, the valve will open too quickly; to prevent this, the difference in size should be no more than half an inch.

To increase pressure, a plastic seal is often used, which is fixed in the area of ​​the inlet hole.

The connection method for each device is slightly different, so we highly recommend reading the certificate and checking the passport when purchasing a certain model. The instructions describe in detail the installation of each individual valve.

Application area

The scope of application directly depends on the valve material. A part whose main material is brass is not used in aggressive environments, say, for control diesel fuel, liquids with an acid base.

Solenoid valves are used to control hydraulic and pneumatic systems, to control cylinders or large industrial valves with large diameters.

Most often, production uses a valve for mechanisms and devices where a limited supply of water, gas, air, etc. is necessary. – washing machine, dishwasher, heating system control. The double action pulse valve is used as a device for supplying air and water to dental offices, for watering the land, recharging various appliances with diesel fuel, monitoring the operation of a machine with a mini-gas installation, and even for a refrigerator.

Price overview

You can buy a solenoid air, deluge or gas valve with a power of up to 380 volts in Russia, Ukraine, Belarus at any specialized store. You will find devices of this type: freon, Honda, SVM, CEME, SKN for a variety of installations. Each manufacturer offers its own price list; we have collected average prices for valves produced in Russia, Italy, Germany and the CIS countries:

All companies provide a one-year warranty on their products; sales are carried out in official dealer stores.