Modern gas equipment in heat supply systems involves the use of a wide range of pipeline fittings. These are the means of regulation, protection and control that ensure the stable and safe operation of the target unit. Thus, a new generation of valves is an electromagnetic gas valve designed to distribute and regulate the flow of the working mixture.
Design fixture
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, pistons, a spring block and a stem with a plunger, which directly control the gas solenoid valve, make up the working structure. The design of the coil may differ depending on the type of medium and its pressure, but most oftenit is a winding with a high-quality enamel wire in a dustproof case. The cores are made of electrical copper.
Depending on the type of equipment, different configurations of the connection system may be used. For geysers, a flanged or threaded method of interfacing with a pipeline is usually used. The network connection in the case of household circuits is carried out through a 220 V plug. In the future, the electromagnetic gas valve can be supplemented with auxiliary fittings and control and measuring devices.
Performance properties of materials
Because valve fittings are initially oriented to special conditions of use, 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 a 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 handles well with butane and propane mixtures, but at the same time is afraid of strong oxidizing agents and ultraviolet.
Solenoid valve working principle
The state of the valve is affected by an electromagnetic coil, the pulses 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 provided by a spring block and 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 exposure to a 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 drops.
Features of a normally open valve
The principle of operation of the most common statically closed design was described above. In the case of a normally open valve, the regulation is carried out differently. ATIn 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.
Varieties of device
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 redirection of the working medium to one or another circuit. Devices with four channels actually act on the principle of a collector, distributing gas through different supply lines.
Conclusion
In choosing the right shut-off valves, it is important to take into account many technical and operational parameters. At a minimum, you should rely on the design and electrical characteristics that 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 a long service life. With regard to the connection configuration and principle of operation, the choice should be made based on the nature of the operation of the column, the volume of gas supply and other nuances of the equipment.
