For water, it is designed to regulate the passage of liquid. The device operates on an electromechanical principle. For the manufacture of the body, resistant and universal, as well as high-strength materials such as cast iron, brass, of stainless steel. As for membranes and seals, they are made of highly elastic polymers. Among other things, the composition may contain silicone rubber.
Such a device is installed in that part of the pipeline system to which easy access will be provided.
Solenoid valve design
Also called solenoid. It consists of main parts such as a membrane, housing, spring, cover, rod, and also a solenoid. The valve cover and body are cast from stainless steel, brass, polymers or cast iron. These devices are designed for operation in a wide range of operating environments, temperatures and pressures.
Magnetic materials are used for rods and plungers. Electric coils, called solenoids, are manufactured in a dust-proof or sealed housing. High-quality enamel wire is used for winding the coils. It is made of electrical copper. The connection to the pipeline system can be made using the slate or threaded method. To connect to electrical network plug is used. Control is carried out by applying voltage to the coil.
Leading working positions
If we consider the above-described devices according to their design, they can be normally closed or normally open. Among the varieties, we can also distinguish bistable valves, which are called pulse valves. The control principle facilitates switching from closed to open position.
Operating principle
Can be used for different conditions, this involves the use of direct-acting devices, as well as devices that operate at zero pressure drop. On sale you can find indirect-acting valves that are pilot valves. They operate exclusively at the smallest pressure drop.
Such devices can be divided into three-way distribution, shut-off and switching valves.
Information about seals and membranes
The solenoid valve for water contains membranes that can be made of elastic polymer materials. The latter have a special design and chemical composition. Among other things, the latest compositions and other polymers are used in the design of the valves.
Operating principle of pilot valve
A solenoid valve for water can be installed quite quickly with your own hands. If we are talking about a normally closed device, then in the static position there is no voltage, and the valve is in the closed state. The piston, which is a shut-off organ, is pressed hermetically; it is located at the seat of the sealing surface. The pilot channel is in a closed state. The pressure in the upper cavity is maintained using a bypass hole in the membrane.
This type of valve remains closed until the coil is stressed. In order for it to open, voltage must be applied to the coil. Under influence magnetic field the plunger rises, opening the channel. Due to the fact that the diameter of the channel is much larger than the bypass, the pressure of the upper cavity decreases. The pressure difference causes the piston or diaphragm to rise, causing the valve to open. The water supply solenoid valve will remain open as long as the coil is energized.
Operating principle of a normally open valve
This device works on the reverse principle: in a static position the device is in open form, but when the voltage increases, the valve closes. In order to keep the device closed, voltage will be supplied to the coil for a long time. In order for any pilot valves to operate properly, a low pressure drop must be maintained.
Such devices are called indirectly acting valves for the reason that in addition to supplying voltage, a condition must be met, which is a pressure difference. This device can be used for heating systems, water supply, hot water supply, as well as pneumatic control. The unit is suitable for conditions where there is pressure in the pipeline.
Direct acting valve operation
An electromagnetic valve, the diagram of which makes it possible to understand the principle of operation, can have direct action. This device does not have a pilot channel. In the central part there is an elastic membrane that has a metal ring. It is connected to the plunger through the spring. When a magnetic field is applied to the coil, the valve opens, the plunger rises and relieves the force on the membrane. The latter rises and helps open the valve. At the moment when closing occurs, there is no magnetic field, the plunger lowers and acts on the membrane.
For such a device, a minimum pressure drop is not required. The solenoid valve, a photo of which is presented in the article, can be used in pressure systems, as well as on drain tanks. The device can also be installed in storage receivers. Such a device can be installed in places where there is no pressure or is at a minimum level.
Features of the bistable valve
This valve can be in two stable positions: closed and open. Switching is carried out sequentially by applying a pulse to the coil. Such devices operate exclusively from a source direct current. To keep the valve closed or open position, no voltage required. By design, such devices are made as pilot ones, this indicates the need for a minimum pressure drop.
Electromagnetic solenoid valve represents a reliable and functional fitting for the pipeline system. If we are talking about special electromagnetic coils, then their service life is very long. Until the device fails, it can operate until the number of starts reaches 1 million. The time it takes for the magnetic valve to operate can range from 30 to 500 milliseconds. The final figure will depend on the pressure, diameter and design.
Conclusion
Device solenoid valve was presented above, as well as the principle of its operation. Similar devices can be used as a locking device remote control. They are indispensable for safety in the role of shut-off, shut-off and switching electric valves. These features must be taken into account before purchasing a valve and installing it in certain conditions.
An electromagnetic valve, or solenoid valve as it is also called, is a type of shut-off valve with an electromechanical operating principle. It performs automation functions and remote control directions of gaseous and liquid working media in the pipeline. Metered supply of the required volume of flow at a time is ensured using an electromagnetic coil.
The solenoid valve is widely used both at the domestic level and in large industrial systems. Over a wide range of operating temperatures. The electromagnetic valve regulates the flow of the medium. , .
Operating principle and design of solenoid valve
In the production of the solenoid valve, materials are used that meet the requirements of GOST and international standards. The solenoid valve consists of the following elements:
In this case, the body can be made of,. placed in a sealed housing, and the winding is made of high-strength technical copper. To ensure maximum tightness, materials such as heat-resistant rubber, silicone, rubber, fluoroplastic, and polytetrafluoroethylene (PTFE) are used for manufacturing. Stainless steel is also used for production.
The operating principle of the solenoid valve is based on the operation of an element such as an electromagnetic coil. When there is no direct or alternating current on the coil, then under mechanical impact the springs, diaphragm or valve piston are located in the seat of the device. However, when voltage of varying power is applied to the solenoid, the plunger is pulled into the coil, thereby opening or closing the flow hole. Stopping the voltage supply to the coil causes the valves to close. The solenoid valve may have different design features which depend on its type.
Types of Solenoid Valve
Solenoid valves are divided according to the type of operating position, operating principle, connection to the pipeline, sealing membrane and piston seal.
According to the type of operating position, valves are:
· Breakdown induction coil caused by incorrect voltage power supplied to the coil or exceeding the temperature or pressure limits inside the pipeline, also moisture entering the coil can cause short circuit and coil combustion. This malfunction can be corrected by replacement. You can also set to prevent the coil from overheating.
· If the valve does not open and close completely, this may be caused by a clogged control hole, a defective diaphragm, gasket or piston seal, as well as residual voltage on the coil.
Solenoid valve repair is carried out by qualified specialists who have access to work with electrical networks.
Production of solenoid valves carried out in special factories pipeline fittings, which are located in almost every country in the world.
Solenoid Valve Cost depends on its functions, type of design, diameter, company manufacturer of electromagnetic (solenoid) valves. Our specialists can help determine the required type of device.
Automation of processes for controlling the flow of steam, air, water or other media is a natural development of industry. Therefore, shut-off solenoid valves are widely used in pipelines and automatically controlled systems.
Such devices are two-position actuators. They are installed on pipelines for fresh water, air, freon, ammonia and so on. Moreover, there are modifications designed to work with one specific substance, for example, ammonia.
Features and Application
The solenoid valve is an effective regulating or locking device for operational remote control of flows of various media in pipelines. It is the most popular among all electromagnetic valves.
For their production, electromagnets are used that have fixed parts, precisely called solenoids. Actually, hence the name.
A Danfoss valve for water or other media consists of the following elements:
- frame;
- coil solenoid valve and core;
- a piston or disk that controls the flow of a working fluid.
The materials used for the manufacture of Danfoss solenoid valves are:
- stainless steel;
- brass;
- plastic.
Gaskets, seals and diaphragms are made from:
- silicone;
- fluoroplastic;
- rubber;
- rubber.
The Danfoss solenoid has virtually the same operating principle as a conventional shut-off valve. However, it has a significant difference: its closing or opening occurs due to the supply to the coil electrical voltage, that is physical effort not attached .
Using such a device, you can remotely submit required amount liquid, gas or steam at the right time. Therefore, the scope of solenoid applications is very wide.
The principle of operation can be described as follows. Static position - the coil is de-energized, it is in a closed state (it can be open - it all depends on the type of product).
The piston or membrane is pressed against the valve seat by the action of a spring. When voltage is applied to the coil, it opens. The magnetic field generated in the solenoid acts on the plunger.
Types and differences
There are two main types:
- direct;
- indirect action.
The former open when current passes through the coil, and close when the coil is turned off.
Indirect-acting devices operate based on the pressure difference between the outlet and inlet. When there is no current in the coil, the core is lowered and the auxiliary is in the closed state. The pressure level above and below the membrane is the same and corresponds to the condensation pressure. The cavities communicate through a calibrated hole.
The main valve is in the closed state because it is acted upon by the auxiliary spring and its own weight. When current passes through the coil, the core rises, the auxiliary goes into the “open” state.
The medium above the membrane leaves through a channel in the product body. There is a decrease in pressure above the membrane, because the cross-section of the auxiliary and bypass valves larger size calibrated hole.
Due to the resulting pressure difference above and below the membrane, the main valve opens.
Solenoid valves can be produced in regular or explosion-proof versions - it all depends on the premises. The latter option is widely used in oil and gas production systems, gas stations, fuel depots and other similar facilities.
Based on their operating features, devices are divided into three groups:
- normally closed;
- normally open;
- customizable.
The first option: in a calm state it is closed, but it opens when the coil is energized.
Fine open devices open when at rest. Customizable samples allow you to configure them into a convenient operating mode.
Considering the type of design, products can also be:
- ordinary;
- combined.
The first ones are standard shut-off valves. The latter perform the functions of a mixer, since they have three inputs. Combined - the most complex devices, are used in special conditions, are made to order.
Devices are also classified according to the type of workplace. For example, for water, for oil, and so on.
Let's consider the main advantages of the products:
There are also disadvantages:
- the cost of the product is slightly higher than the average price for a regular shut-off valve;
- if operation is not carried out according to the instructions, the device may fail;
- Electrical connection required.
Selection and characteristics
When choosing a shut-off solenoid device, you should pay attention to the characteristics and design features. For example, not all products allow you to direct the flow in any direction.
Some models can only work in one direction. If this condition is not taken into account when choosing a product, the device will partially or completely fail when used in such unfavorable conditions.
However, the first thing to consider is the environment in which the device will operate.
An important characteristic is the internal and outside diameter, which can be expressed in either inches or millimeters. Many models can withstand pressure up to 10 bar.
The reliable Danfoss valve is quite popular on the domestic market. There are several types that the manufacturer offers to choose from:
- The EVR series is characterized by flexibility and high reliability. A popular model is the Danfoss EV220B solenoid valve. This series is a direct action mechanism used for air conditioning systems, freezing and refrigeration units.
- EVRA and EVRAT series. This Danfoss solenoid valve is a direct-acting valve, used in hot gas pipelines with refrigerants.
- STF and VHV. These 4-way valves can provide heating in winter and cooling in summer.
The price of a Danfoss solenoid valve can start at $150.
Features of application (video)
Before installing the valve, the pipeline must be cleaned, since the entry of foreign particles can lead to its failure. Therefore, a filter is installed in front of the inlet of the product.
The direction of the arrow marked on the valve body must coincide with the direction of the medium flow. Otherwise, the device will quickly break down.
The pipes at the ends of the valve must be properly secured. When tightening, use two wrench, that is, it is necessary to apply counterforce. Installation, as a rule, is carried out using dismountable joints, although welding can also be used, although this will complicate the maintainability of the product.
The cable connection point must be insulated: you can use electrical tape and sealant. Before connecting the power supply, make sure that the coil parameters correspond to the network parameters. Otherwise, it will cause the element to break.
There are three options:
- middle – grounding (yellow-green wire);
- the other two are phase and zero of the source.
First, the valve must be energized so that a characteristic click is heard. If everything is in order, you can proceed to the test run.
A cylindrical winding that has a length significantly greater than its diameter is called a solenoid. Translated from English, this word means “like a pipe,” that is, it is a coil similar to a pipe.
Device and principle of operation
A solenoid can also be called an inductor coil, which is wound with a wire on a frame in the form of a cylinder. Such coils can be wound in one or several layers. Since the length of the winding is much greater than the diameter, when a constant voltage is connected to this winding, a voltage is formed inside the coil.
Electromechanical devices that contain a coil with a ferromagnetic core inside are often called solenoids. Such devices are made in the form of retractor relays of a car starter, various electric valves. The retracting element of such a unique electromagnet is a core made of ferromagnetic material.
If there is no core in the solenoid device, then when direct current is connected, a magnetic field is formed along the winding. The induction of this field is equal to:
Where, N– number of turns in the winding, l– coil length, I– current flowing through the solenoid, μ0
At the ends of the solenoid, the magnitude of magnetic induction is two times lower compared to internal part, since the two parts of the solenoid jointly form a double magnetic field. This applies to a long or endless solenoid compared to the diameter of the winding frame.
At the edges of the solenoid, the magnetic induction is equal to:
Since solenoids are inductors, hence the solenoid can store energy in a magnetic field. This energy is equal to the work done by the source to generate current in the winding.
This current forms a magnetic field in the solenoid:
If the current in the coil changes, then a self-induced emf occurs. In this case, the voltage on the solenoid is determined:
The solenoid inductance is determined by:
Where, V– volume of the solenoid coil, z– length of the coil conductor, n– number of turns, l– coil length, μ0 - vacuum magnetic permeability.
When connecting an alternating voltage solenoid to the conductors, the magnetic field will also be created as alternating. The solenoid has resistance to alternating current in the form of a complex of two components: . They depend on the inductance and electrical resistance of the coil conductor.
Types of solenoids
According to their purpose, solenoids are divided into two classes:
- Stationary. That is, for magnetic fields stationary type, which last a long time at certain values.
- Pulse. To create pulsed magnetic fields. They can only exist for a short period of time, no more than 1 second.
Stationary capable of creating fields of no more than 2.5x10 5 Oe. Pulse-type solenoids can create fields of 5x10 6 Oe. If, when creating a field, the solenoids are not subject to deformation and do not get too hot, then the magnetic field directly depends on the passing current: Н = k*I, Where k– constant value of the solenoid, amenable to calculation.
Stationary ones are divided:
- Resistive.
- Superconducting.
Resistive solenoids are made from materials that have electrical resistance. In this regard, all the energy approaching them turns into heat. To avoid thermal destruction of the device, it is necessary to remove excess heat. For these purposes, cryogenic or water cooling. This requires auxiliary energy comparable to the energy required to power the solenoid.
Superconducting solenoids are made from alloys with superconducting properties. Their electrical resistance equals zero at different temperatures during the experiment. When a superconducting solenoid operates, heat is generated only in suitable conductors and a voltage source. In this case, the power source can be excluded, since the solenoid operates in short-circuited mode. In this case, the field can exist without energy consumption for an infinitely long time, provided that superconductivity is maintained.
Devices for creating powerful magnetic fields include three main parts:
- Solenoid.
- Current source.
- Cooling system.
When designing a solenoid, the dimensions of the internal channel and the power of the power source are taken into account.
The creation of a device with a resistive solenoid for the formation of stationary fields is a global scientific and technical task. In the world, including in our country, there are only a few laboratories with similar devices. Solenoids are used various designs, the operation of which is carried out near the thermal boundary.
To maintain such devices, a staff consisting of highly qualified workers is required, whose work is highly valued. Most of the finances are spent on payment electrical energy. The operation and maintenance of such powerful solenoids pays off over time, as scientists and researchers from various fields of science, from different countries can obtain the most important results for the development of science.
The most complex and important problems can be solved by using superconducting solenoids. This method is more effective, economical and simple. For example, we can mention the creation of powerful stationary fields by superconducting solenoids. Most original property superconductivity is the absence of electrical resistance in some alloys and metals at temperatures below a critical value.
The phenomenon of superconductivity makes it possible to produce a solenoid that does not dissipate energy during passage electric current. However, the generated field has a limitation in that when a certain value of the critical field is reached, the property of superconductivity is destroyed and the electrical resistance is restored.
The critical field increases as the temperature decreases from 0 to the highest value. Back in the 50s of the last century, alloys were discovered whose critical temperature is in the range from 10 to 20 K. Moreover, they have the properties of very powerful critical fields.
The technology for creating such alloys and producing materials for solenoid coils from them is very labor-intensive and complex. Therefore, such devices have a high cost. However, they are inexpensive to operate and easy to maintain. This requires only a low voltage power supply of low power and liquid helium. The source power will need no more than 1 kilowatt. The device of such solenoids consists of a coil made of copper and a superconductor stranded wire, tape or tire.
It is possible to reduce energy costs to create even more powerful fields. This opportunity is being implemented in several leading countries, including Russia. This method is based on the use of a combination of water-cooled and superconducting solenoids. It is also called a hybrid solenoid. This device integrates the highest achievable fields of both types of solenoids.
The water-cooled solenoid must be located inside the superconducting one. The creation of a hybrid solenoid is a voluminous and complex scientific and technical problem. Solving it requires the work of several teams of scientific institutions. A similar hybrid device is used in our country at the Academy of Sciences. There, a solenoid with superconducting properties has a mass of 1.5 tons. The winding is made of special alloys of niobium with zinc and titanium. The winding of the water-cooled solenoid is made of a copper busbar.
An electromechanical shut-off element that performs the function of remote automatic control of the directions of movement of the liquid and gaseous working medium inside the pipeline. Using an electromagnetic coil, the required volumes of flow are dosed into the certain moment time.
Widely used at the household level and in large industrial structures over a wide range of operating temperatures. In housing and communal services pipelines, the valve regulates the environment inside the water supply or sewer systems, central heating. Used on technological lines of chemical and oil refineries, filtration hydraulic pipelines. Applicable in agriculture: irrigation structures, dosing and mixing systems.
Principle of operation solenoid valve
For production of solenoid valvesmaterials are used that meet the requirements of GOST and international standards. Solenoid valve consists of several main elements:
How does a solenoid valve work?
Principle solenoid valve operationbased on the operation of the control - electromagnetic coil . In the absence of permanent or alternating current under mechanical pressure, the springs and membrane (piston) of the valve are located in the seat of the device. When electrical voltage of varying power is applied to the solenoid terminals, the core is drawn into the coil, ensuring the opening or closing of the duct opening. De-energizing the solenoid causes the valves to close. Design featuressolenoid valve devicesmay vary depending on its type.
Types solenoid valves
Solenoid valves are divided into several categories.
By type of working position there are:
Normally open valves. By default, the valve element is in the open position and does not interfere with the flow.
- Normally closed valves. The absence of voltage on the coil is characterized by closed position shutter
Bistable valves. Capable of switching to open or closed position under the influence of an electrical impulse.
Based on their operating principle, solenoid valves are divided into:
Direct acting valve. the position of the gate component changes under the influence of the movement of the core when electrical voltage is applied.
Indirect acting valve. The influence of the energy of the working environment leads to the opening and closing of the conditional passage. It is controlled remotely by a pilot valve, which is activated when electrical current is applied to the coil.
Bistable valves. The shutter is adjusted according to principle membrane elevationsolenoid valve.
By type of connection to the pipeline:
By type of sealing membrane:
Membrane FKM (fluoride rubber). Standard seal, suitable for most non-aggressive media.
NBR membrane (nitrile butadiene rubber). Used in petroleum products: gasoline, oils, kerosene, diesel fuel.
EPDM membrane (ethylene-propylene rubber). Characterized by increased resistance to temperatures, works in environments chemical solutions and compounds: alkalis, alcohols, glycols, ketones, water, etc.
Installation and operation rules
Any installation work with the valve are carried out in the absence of a working medium in the system and the electrical circuit is de-energized. Before starting work, the pipeline should be cleared of mechanical particles and suspensions.
How to connect solenoid valve. Connecting solenoid valvesin the system it is carried out in a horizontal position, with the coil up.
For proper operation device, the direction of movement of the medium must correspond to the index arrow on the housing.
Installation of the solenoid valveis carried out in a place accessible for subsequent repairs or maintenance.
It is prohibited to install the valve in places with high rates of condensation or vibration, areas with possible icing of the pipe, near leaks and gusts.
Installing additional strainers of a suitable size will protect the valve from contamination and, as a result, a decrease in its hydraulic characteristics.
Advantages of solenoid valves
Automatic type of operation
High performance
Remote control capability
Compactness (small size and weight)
Long service life
Easy installation and maintenance
Causes of breakdowns and methods of elimination
Correct use and compliance technical parameters specified in the product passport will ensure reliable and long work devices. In some cases, prematureSolenoid valve malfunctionpossible for several reasons.
A decrease in the tightness of the product can be caused by mechanical particles entering the device seat. It is recommended to dismantle and clean the device and then install it in the system mesh filter to the valve.
Failure of the induction coil may be caused by incorrect voltage supplied to the terminals or by exceeding the temperature and pressure limits inside the pipeline. The device should be dismantled and the coil replaced. Moisture on the coil may cause a short circuit and damage the device.
Incomplete opening/closing of the valve may result from contamination of the control hole, defects in the membrane or gasket, residual voltage on the solenoid, etc.
Solenoid valve repairmust be carried out by a qualified specialist licensed to work with electrical networks.
Production of solenoid valvescarried out at specialized pipe fittings factories located in almost every country in Europe. One of the world's leading manufacturers of solenoid valves is SMART HYDRODYNAMIC SYSTEMS. Solenoid valve costdepends on its functions, design type, thread diameter and company -manufacturer of electromagnetic (solenoid) valves.For determining required type devices can be consulted with specialists or viewedvideo of solenoid valve.
