Solenoid valves for gas. Description and characteristics

Any electric machine works thanks to the presence of many special parts. We offer to consider what a normally closed solenoid valve is, its principle of operation 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, automatic transmission, KSVM, ZSK, ISP, Burkert, KSP). This valve is controlled by electric current, which passes the 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 applied, or the flow valve will close. When the current stops flowing to the valve coil, it will return to its normal state.

Mechanisms are:

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

Direct acting electric valves open and close an orifice inside the valve. In experimentally controlled valves (they are also called shut-off devices), the piston opens and closes the hole. in valves high pressure(for example, flange valve) pistons and special seals are used to control the state of the hole.

Video: solenoid Danfoss valves

Description of the construction of the standard device

The simplest solenoid solenoid valve has two ports: at the input and output. 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 is closed by a piston (7).

The solenoid valve in the photo above is a normally closed solenoid valve type ASCO, TORK or Danfoss. 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 a protection (gasket) against water or gas entering the holes, as long as the piston is lifted by electric magnetic field generated by the coil. The diagram demonstrates the operation of the standard.

There are many valve design variations. Conventional valves may have multiple ports and pistons. The two-way valve of indirect action (return) has 2 ports - EV1140, DU50, DU32, DU100, DU15, DU25, RU16 series; if the valve is open, two ports are connected and liquid moves between them; if the valve is closed, the ports are isolated. 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 port and more complex device designs, their designation looks like 30 (3, 33, etc.). The three-way valve has 3 ports for motor control; it connects one port or two of them (usually an intake port and an exhaust port).

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

Fs \u003d P * A \u003d P * pi * d 2 / 4

Where d is the hole diameter.

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

The design and purpose of the piloted valve

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

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

Pressurized water enters the chamber. The inlet is an elastic membrane, and above it is a spring that pushes it down. The diaphragm has a hole through the center, it allows you to control the amount of water, often a very small part is skipped. 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. So the spring has nothing to do with closing or opening the valve.

If current is passed through the diaphragm solenoid, the water in the chamber flows out through the direct passage faster than the chamber is replenished. The incoming pressure raises the diaphragm.

When the solenoid turns off again, the passage is closed by a spring, very little force is needed to push the diaphragm down, the main valve closes again. In practice, there is often no separate spring; The elastomer diaphragm is adapted so that it works like its own source, mostly in a closed form.

It can be seen from the explanation that this type of valve depends on the pressure difference between inlet and outlet, since for it to work, the inlet pressure must always be greater than the outlet pressure. If the outlet pressure is, for any reason, higher than the inlet pressure, the valve will open too quickly for this to be prevented by a difference in size of less than half an inch.

Often used to increase pressure plastic seal, which is fixed in the area of ​​\u200b\u200bthe inlet.

The connection method for each device is slightly different, so we highly recommend that you read the certificate when buying, check the passport of a specific model. The instructions describe in detail the installation of each individual valve.

Application area

The scope of application directly depends on the material of the valves. The part, the main material of which 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, feeding various appliances with diesel fuel, controlling 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 (CEME), SKN for a variety of installations. Each manufacturer offers its own price list, we have collected average prices for valves made in Russia, Italy, Germany and the CIS countries:

All companies provide a guarantee for their products for a year, the sale is carried out in official dealer stores.

Large selection of solenoid valves used in gas communications. The body of the product is brass, strong and durable. Products have the function of manual cocking and belong to normally closed valves (opens if the stem is cocked and electricity is connected). The manufacturing company is European.

All types of this equipment are available, with flanged and threaded connections.
The proposed products remotely control gas flows, shutting it off if necessary (if the product is used in conjunction with a gas detector). Closing will take no more than one second.

Designed for industrial and domestic use.

Versions EVGNС

How the EVGNC valve works

In the absence of voltage, the EVGNС valve is closed, and in the presence of voltage and the stem is cocked, it opens. When the EVGNC valve is operated, for example, with a gas detector, after a gas leak occurs, the alarm relay contacts close, the valve is energized, and the valve shuts off the gas supply. Closing time less than 1 sec. To open the valve, cock it using the cocking rod.

Specifications of gas shut-off valve normally open with manual cocking EVGNС

Overall dimensions of the normally closed gas shut-off valve with manual cocking EVGNС

PRICE for EVGNC valves

Solenoid gas valve is one of the devices pipe fittings, designed to distribute and regulate the working environment in gas supply systems, as well as on gas pipelines. Home distinctive feature solenoid gas valve is remote control which is carried out with the help of electricity. An electrical impulse initiates the movement of an electromagnet in a given direction, which in turn sets the movement of the shutter.

Solenoid gas valve device

The working element of a gas solenoid valve is a seat - an opening located inside the body for the passage of the working medium, as well as a shutter. Depending on the model and configuration of the device, the shutter can be made both in the form of a plate and in the form of a piston. Making reciprocating movements, the shutter opens or shuts off the gas supply. It is mounted on a magnetic rod (core), which is connected to an electromagnet. The electromagnet coil itself is installed in the upper part of the body on the outside of the valve.

Gas solenoid valve: principle of operation

The principle of operation of the electromagnetic gas valve is that when electricity is applied to the coil, a magnetic field is created. Under the influence of this field, the electromagnet is drawn into the coil, and thereby sets the direction of movement of the shutter.

During operation, the valve is subjected to two forces - on the one hand it is the force of resistance to the return spring, and on the other hand it is the force of the magnetic field. The latter is regulated by the strength of the electric current - the stronger the electric current, the higher the force with which the influence of the spring is overcome. Thus, by adjusting the current supply, it is possible to regulate the degree of opening or closing of the electromagnetic gas valve, and, consequently, the supply of the working medium.

When the power is turned off, the valve returns to its original position, which is determined by its design.

Varieties of electromagnetic gas valves

All models of gas solenoid valves that exist today can be divided into three large groups:

Normally open (NO). When the normal electricity supply is turned off, the open gas valves are in the open position, ensuring the free passage of the working medium.

• Normally closed (NC). Normally closed solenoid valves without power supply come into a closed state, thereby shutting off the flow of gas in a pipeline or any system.
• Universal. The universal gas solenoid valve is designed in such a way that it can remain in either the closed or open position in the event of a power outage.

As for other differences, here we can highlight solenoid gas valves direct and indirect action. The former assume that the valve plug is actuated only by the movement of the core; the latter use not only the core to move the shutter, but also the force of the working medium, which can significantly save effort during large passages.

Solenoid gas valves also differ in the number of strokes. Currently there are:

Two-way valves with only inlet and outlet. Devices of this type are intended solely for supplying or blocking the working medium into any system.

• Three-way valves with one inlet and two outlets. Such an electromagnetic gas valve can not only pass, but also redirect the gas flow in the system.
• Four-way valves are devices that have four holes - one inlet and three outlets. Like three-way valves, they can redistribute the flow of the working environment, but unlike them, they give more possibilities to connect to various systems.

It should be noted that inside each type of electromagnetic gas valves there are many models and modifications of these devices, differing both in size and functionality. For example, in accordance with the operating conditions, some valve models may have a special coating that is resistant to aggressive media.

Where to buy a solenoid gas valve?

Solenoid gas valves are devices that operate on gas pipelines, and their failure can lead to the most backfire. That is why valves must meet the most stringent requirements for their safety and reliability. And this means that you need to purchase them only from a well-established manufacturer.

JSC "Penza Valve Plant" is an enterprise with more than half a century of history. During the operation of the plant, our devices have repeatedly proved their highest quality and unsurpassed reliability. Therefore, if you need to purchase pipeline fittings, we recommend that you pay attention to the products of PAZ OJSC, among which various models of electromagnetic gas valves are presented.

Multifunctional solenoid valves for gas belong to the category of pipeline fittings. Devices are used for distribution, regulation, cut-off of the working medium in boilers, geysers, pipelines and other gas equipment. The magnetic valve of the valve is controlled remotely, in automatic mode, this is its advantageous feature. The relay turns on or cuts off the supply of electric current to the coil, the plunger rises or falls, opening or closing the hole, thereby controlling the gas flow.

The price of a solenoid gas valve is higher than similar mechanical devices. The cost of its acquisition is paid off due to the ability to conduct technological optimal mode with minimum fuel consumption. In addition, the devices are recommended for installation, since they greatly increase the safety of operation of boilers, columns, and furnaces. In the event of a fuel leak, the magnetic choke will immediately cut off the gas supply, thereby preventing the dangers associated with concentration harmful substances in room.

Multi-purpose fittings are used for servicing domestic and industrial installations, automotive systems.

Device, principle of operation

The main elements are the saddle and the shutter. The seat can be in the form of a piston or a plate, the valve configuration is different, depending on the modification. The shutter is mounted on a core connected to an electromagnet. Opening and cutting off the gas supply occurs due to the reciprocating movements of the shutter. The magnetic mechanism is mounted on the outside of the valve body.

When an electric current is applied to the magnetic component, a magnetic field arises, which forms the direction of movement of the shutter. At the time of valve operation, the electromagnetic assembly is affected by the resistance force to the return spring and the magnetic field, the strength of which depends on the strength of the operating current. When the device is disconnected from the mains, it returns (remains) to the position determined by the type of its design.

Alloys are used for the manufacture of valve body and covers stainless steels, brass, cast iron, polymers (environmentalist, nylon, polypropylene). Plungers and rods are made of magnetic compositions.

The valve is connected to the pipeline by means of a flange or threaded connection. To the electrical network - using a plug.

Varieties

Solenoid valves are characterized by a variety constructive solutions, so they are classified according to many parameters.

According to the method of opening, valves are distinguished:

• normally open (NO); they remain in the open position when the power supply is interrupted, thereby providing conditions for the passage of the maximum volume of flow;
• normally closed (NC): in the absence of current solenoid gas shut-off valve NC is closed, thereby completely blocking the passage of the flow;
• universal: such models can remain in the open or closed position during a power outage.

In modified modern models the possibility of reconfiguring the pilot position of the membrane is provided. Devices with NO plug position can be converted to NC type valves.

According to the type of execution, the valves can have a conventional or explosion-proof design. The latter are recommended for installation at facilities that have high requirements for explosion fire safety (chemical, petrochemical, gas and other industries).

Solenoid valves for gas It is also customary to classify according to the features of control into direct-acting devices and driven by a piston (membrane force).

• Direct acting valves are characterized by simple design, fast response and high reliability. In such models there is no pilot channel. Opening occurs instantly when the membrane is lifted. In the absence of a magnetic field, the spring-loaded plunger is lowered. Models of this type do not require a differential pressure to operate.
• Models with piston (diaphragm) force are equipped with two spools. The main function is to close the main hole, the control spool is responsible for the operation of the relief hole, which serves to relieve pressure from the area above the membrane. Due to pressure compensation, the main spool rises, the main passage opens.

According to the number of pipe connections, electromagnetic valves are classified into two-, three- and four-way valves. Two-way valves are NC or NC type, they have one inlet and one outlet pipe connection. In three-way, three connections and two flow sections are provided. They are NO, NC type and universal, they are in demand for organizing the operation of automatic drives, control valves, cylinders with one-way vacuum action, and alternate pressure supply. Four-way are completed with four or five pipe connections. One connection for pressure, one or two for vacuum, two for cylinder. Such models are necessary for the operation of automatic drives, double-acting cylinders.

The solenoid valve for water, gas, oil products, which has a shut-off and control design, is actively used in modern industry. The valve allows you to remotely control heating and thermal equipment, as well as gas flows in pipelines. With the use of a gas solenoid valve, the general security systems, with low power consumption, the equipment is highly reliable and long term service with sufficient purity of the fuel (no inclusions of mechanical impurities).

Main types of solenoid valves

1. Solenoid shut-off valve for use on pipelines through which only liquid media or gases. This equipment works as part of air conditioning, ventilation, oil products, gas and steam systems.
2. Valves with pneumatic drive.
3. Explosion-proof and intrinsically safe valves.
4. Devices that allow you to control pneumatic actuators
5. Valves for special purposes (solenoid solenoid valve that work with cryogenic working media, gas stations, vacuum plants).
6. Electropneumatic distributors.

The manufacturers presented today create normally closed solenoid valves. In the presence of a manual cocking of the shutter, an automatic overlap occurs, which is triggered when a signal is received on the coil (electromagnet). All fuel solenoid valves are a tool to increase the safety of the facility, since in the presence of malfunctions and the operation of the equipment, they must be assembled.

Our company is actively working on the design and development of new modifications of solenoid valves. Call, contact, we are always ready to provide detailed advice on all questions.