Electromagnetic gas valves: purpose, device, types, installation. Solenoid valves for gas. Description and characteristics Device, principle of operation

Gas equipment protection systems cut off the flow of energy in the event of emergencies. Operation without them gas installations prohibited. The elements of protection are gas valves electromagnetic type.

Solenoid gas valves

Devices of this type belong to pipeline fittings and are used to distribute the gas flow and cut it off if necessary. They are widely used both in individual gas equipment and in industrial ones. The device is controlled automatically under the action of voltage.

Solenoid gas valves are placed at the inlet of the gas pipeline in front of such consumers:

• boilers;
• automotive gas equipment;
• pipe entry into a multi-storey building.

Most gas valves have a closed design, that is, in the absence of voltage, the valve closes the pipe.

The device of gas solenoid valves

Gas valves of electromagnetic type consist of electrical and mechanical parts. With the help of the electrical one, the system is controlled, the mechanical one is the actuating element. The entire circuit of the device is located in the case. The main working components are the so-called seat and plug. The saddle is a hole through which the gas flows and which is blocked by a shutter. The latter has a design like a plate or a piston. The shutter is mounted on a rod, which is part of the electromagnetic system.

The electromagnetic system is a coil inside which the core moves. It is connected to the shutter rod. The solenoid itself has its own plastic housing and is located outside on top of the valve body. Opposition to the work of the electromagnet creates a return spring.

Solenoid gas valves work according to the following principle. In the initial state, when there is no supply voltage at the electromagnet terminals, the return spring holds the shutter in a certain position. This position often corresponds to a closed passage in the valve. As soon as the power has appeared, under the influence of magnetic force, the shutter core is retracted, overcoming the force of the return spring, and the shutter opens the channel. Some valves are brought into working position by manually cocking (opening) the shutter. With the help of the current supplied to the electromagnet, it is possible to regulate the magnitude of the magnetic flux of the electromagnet. Thus, the operation of the valve is controlled, opening it partially, thereby regulating the gas flow.

Types of gas valves

Solenoid gas valves come in various configurations and internal device, but they are all divided into:

• Normally closed (NC). That is, in the absence of voltage, the gas is blocked. These are basically emergency type valves.
• Normally open (NO). The gas passes freely if there is no voltage on the coil, and shuts off when a control signal is applied.
• Universal type. In such devices, it is possible to switch the position of the shutter, which can be either open or closed, in the absence of power to the electromagnet coil.

According to the principle of actuating the shutter, the electromagnetic gas shut-off valve can be of indirect and direct locking methods. In the first case, the core of the electromagnet is assisted by the pressure of the working medium in the event of a shutter actuation. In the second, the shutter is moved only by the electromagnetic force acting on the rod.

Gas valves can perform not only a protective function, but also a distributive one. In this sense, there are devices for a different number of moves:

• Valves of two-way type. These are the most common models of safety valves with one inlet and one outlet. Their main function is to block the channel in any possible emergency situations.
• Three way valves. Diverter valves that provide the ability to direct the flow of gas from an inlet between two outlets.
• Four-way type valves can be built into various complex systems, where there is a need to manage energy carrier flows through three different channels.

In addition to the above features of gas valve modifications, each specific device may have original design different from the standard. So, some valves have insides specially made for work in aggressive conditions.

Installation rules

To properly install on gas equipment solenoid valve, the following requirements must be observed:

• The valves are installed at the inlet of the line immediately after the gas cock and the filter element.
• The arrow on the device indicates the direction of the energy carrier flow.
• The position of the valve is only horizontal or vertical at an angle of 90 degrees.

Conclusion

All work on the installation and maintenance of gas equipment can only be performed by qualified gas service specialists. This must be taken into account, otherwise improper work can lead to sad consequences.

Modern gas equipment in heat supply systems involves the use of a wide range of pipe fittings. These are means of regulation, protection and control, providing a stable and safe work target unit. Thus, a new generation of shut-off valves is an electromagnetic gas valve designed to distribute and regulate the flow of the working mixture.

Fixture design

Solenoid valves are also called solenoid valves, since their basis is formed by a solenoid in the form of a coil. It is enclosed in a metal case, complete with a lid and outlets. In addition, the working structure is made up of pistons, a spring block and a stem with a plunger, which directly control the gas solenoid valve. The design of the coil may differ depending on the type of medium and its pressure, but most often it is a winding with a high-quality enamel wire in a dustproof case. The conductors are made of electrical copper.

Depending on the type of equipment, different configurations of the connecting system can be used. For geysers usually use a flanged or threaded method of interfacing with the pipeline. The mains connection in the case of domestic circuits is carried out via a 220 V plug. In the future, the solenoid gas valve can be supplemented auxiliary fittings and control and measuring devices.

Performance properties of materials

Because it initially focuses on special conditions applications, special plastics are used for the basis of the design. For example, EPDM polymer provides the device with resistance to chemical attack, aging and pressure drops. With this design, the valve can be used in temperature conditions from -40 to 140 °C, but it is not recommended to use it in gasoline and hydrocarbon environments. Another modern variation of the polymer alloy is PTFE. It is polytetrafluoroethylene capable of withstanding high concentration acid mixtures. In this case, contact with aggressive gaseous media and operation in the temperature range from -50 to 200 °C are allowed. The use of PTFE polymer is not recommended where there is a risk of contact with trifluoride chloride and alkali metals. At the same time, protective qualities are not always the main requirement for a solenoid valve. Shut-off gas fittings for the same household supply networks may well be made of inexpensive elastic polymers like nitrile butadiene with a rubber base. This material copes well with the maintenance of butane and propane mixtures, but at the same time is afraid of strong oxidizing agents and ultraviolet radiation.

The principle of operation of the solenoid valve

The state of the valve is affected by an electromagnetic coil, the impulses of which actuate the locking elements. The static position of the valve is characterized by its closed position. In this position, the closing membrane or piston element is hermetically pressed against the outlet circuit, preventing the passage of the working mixture. The clamping force is also provided by direct pressure from the gas mixture from the side of the passage. On the main branch pipe, the electromagnetic gas valve is additionally locked by a plunger until the voltage in the coil changes. At the moment of impact magnetic field in the solenoid, the central channel begins to open, where the spring-loaded plunger is located. As the pressure balance changes on different sides of the valve, the state of the piston group with the membrane also changes. The armature is in this position until the voltage on the coil decreases.

Features of a normally open valve

The principle of operation of the most common statically closed design has been described above. In the case of a normally open valve, the regulation is carried out differently. In the normal position, the locking elements provide a free passage for gas mixtures, and the supply of voltage, respectively, leads to closure. Moreover, the retention of a long closed state for safety purposes is possible only with long-term and stable support of a given voltage. An even more functional solenoid valve for a gas boiler does not operate directly, but with a technological pause. Within a short period of time, the system evaluates whether other safety conditions are met in the mixture circuit. Coil voltage as such does not initiate valve closure. But if the indirect conditions are met, then it fires automatically. The decisive factor, in particular, can be a certain voltage value, the same stability or a given amplitude of pressure drops.

Device Varieties

Valve regulators for geysers are distinguished by the number of output channels. Usually two-, three- and four-way models are used. The basic two-way version has an inlet and outlet channel, and during operation, respectively, serves to supply and close the connecting node. As the design becomes more complex, the number of inlets increases. A three-way gas solenoid valve, in particular, provides not only throughput, but also the redirection of the working medium to one or another circuit. Devices with four channels actually operate on the principle of a collector, distributing gas through different supply lines.

Conclusion

In choosing the right stop valves it is important to take into account many technical and operational parameters. At a minimum, one should rely on structural and electrical specifications, which will allow you to correctly integrate the device into the target channel. As for the protective qualities, it is desirable to give preference to solenoid valves for a geyser with an IP65 insulation class. Such products are characterized by dust, moisture and shock resistance, which ensures long term services. With regard to the connection configuration and the principle of operation, the choice should be made based on the nature of the operation of the dispenser, the volume of gas supply and other nuances of the operation of the equipment.

Solenoid valves KEG-9720 are designed for use in systems remote control gas burners for steam and hot water boilers, heating units, domestic heating installations and in technological pipeline systems for gas flow control as a shut-off and control body and a safety body.
Scope of KEG-9720 valves: installation of gas-fired boiler rooms; in the residential sector public utilities equipped with stoves, water heaters, heating boilers running on gas.
For connection to the gas pipeline, a thread is made in accordance with GOST 6357-73 or flanges in accordance with GOST 12815-80.
Details of the KEG-9720 valve are made of corrosion-resistant materials (aluminum, stainless steel). The valve seat is protected from contamination by an inlet filter.
The valve is equipped with an electrical connection system with built-in rectifier and earth contact.
To connect pressure sensors, control devices, pilot burner piping and other elements, there is a 1/4” threaded pipe in the valve body.
Working position - an electromagnet upwards.

Main technical characteristics of the KEG-9720 valve

Execution of KEG-9720 valves

Note. Solenoid valves KEG-9720 are supplied both as separate products and as part of security systems (SGG6M, SOU-1, STG-1).

Online application

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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 EVGNС 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

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 are transferred. 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.