Colenoidny valve: operating principles, design and application

During the creation of a reliable pipeline experts have to spend a lot of physical strength. Using the solenoid valve can save a large share of the money, and ease of installation.

Figure 1. solenoid valve

What it is

The control unit of the electromechanical type called solenoid valve. They are needed to adjust the volume of the working medium flow (gas, water). It is based on a special type of electromagnetic coil, called a solenoid. valve design is no different from other types of valves, so the principle of operation does not differ a complex system. Sometimes there is an alternative name - solenoid valve, since for producing rods and plungers used magnetic material.

Characteristics:

  1. The compact size and low weight makes installation easy
  2. The solenoids can be interchangeable on a permanent or alternating current
  3. Endures changes in temperature
  4. The maximum allowable pressure indicator above the membrane is estimated at 16 Bar
  5. Delivers the temperature fluctuations in the range -30 to +60
  6. Fires for 0,2s.

How does it work

The operating principle of the solenoid valve, which consists in an automatic mode, a significant difference. If you need to stop the flow, is transmitted by the valve voltage. Depending on the valve core begins to fall or rise, which helps shut off the flow. If the voltage is stopped, the core again occupies its original position and stops moving.

What is in

Each valve, regardless of the characteristics of the structure is placed in a special box. It is made of durable metal: brass or iron. To facilitate the design weight, in modern production sometimes used synthetic polymers are not inferior in strength. Among the most common materials can be identified nylon, polypropylene or ekolon. They are also used for the manufacture of covers.

Figure 2. valve device

The design of the solenoid valve consists of the following elements:

  1. coils
  2. plug
  3. plunger
  4. springs
  5. rod
  6. membranes
  7. Fasteners.

The diaphragm is the primary motor element, which is constructed as a special piston. A feature structure protrudes coil that performs control of the device in the automatic mode.

Figure 3. What is in the valve

Also the main body, the coil is provided with a separate protective structure. Using copper coil made with an enamelled coating. The upper layer serves as a protection that prevents malfunction of first coils. Due to strong metallic shell, the mechanism is able to withstand high pressure. Models of proven popular with manufacturers designs of the pipeline system and other structures, where it is understood work with high pressures.

what are the

There are several common classifications. At the heart of the first moves are proportional figures and their number. Kinds:

  • Shut-off;
Figure 4. Shut-off
  • dispensing;
  • Switching.
Figure 5. switch

The second type of classification depends on the manner in which is located the mechanism and valves:

  • bistable;
  • The normally open (when a voltage is applied, are automatically closed);
  • Normally closed (operating closed and opened after supplying the voltage).

BS (bistable) received the greatest popularity, as controlled by the electric pulse, which occurs through the transmission of remote control. With it, the position of the device: closed or open.

Depending on the material used for the seals and membranes isolated:

  • EPDM;
  • FKM;
  • NBR;
  • PTFE;
  • TEFLON;
  • VMQ.

They have high elasticity performance with the use of technologies for manufacturing rare and chemical compositions. The latest models contain a part of rubber and silicone. With an improved composition increases endurance of up to 250 degrees.

The valves can be divided depending on the withstand voltage:

  • With alternating current AC;
  • With constant current AD.

Each type admits error + 10%. Last designed standard is IP65 designation. According to the classification can be defined:

  1. Pilot (exposure is not carried out directly).
Figure 6. pilot
  1. Act directly.
Figure 7. Straight

These valves act in the presence of a minimum pressure or the absence thereof. It is generally used for the implementation of domestic use, storage or drain receivers. The pilot version has an automatic control. The mechanism is triggered with a minimum difference in pressure indicators.

where used

The use of electromagnetic valves true:

  • The arrangement of sewers. When using a timer can be used to organize the uninterrupted water supply. Often experts expect regular intervals the water supply according to a specified schedule;
  • Dosing. Needed in the industrial, pharmaceutical or chemical industry. Special valves for water contribute to normalizing in the manufacture of products;
  • Irrigation. Organization of adequate irrigation of agricultural land is the basis for obtaining a high yield. It should be a certain interval between waterings;
  • When connecting the modular boilers. By means of the solenoid valve is merged to the main conduit;
  • Helping to organize the normal operation of refrigeration equipment.

Benefits

Thanks to optimum technical characteristics are the following advantages in operation:

  • It allowed the installation process in an environment where there is no pressure;
  • An extensive range of industrial materials;
  • Different operation without replacement of parts;
  • The coils have a wide range of supply current pulse in variability 12-400V;
  • The choice of valves with different number of turns;
  • For connection to a plurality of elements;
  • Automatic control;
  • Ease of installation;
  • Minimal material costs.

In the market there are many models. The successful choice depends on the life of the device and how much industrial activity will be implemented effectively.

How to choose

Before purchasing a particular variant of the valve, it is recommended to get acquainted with the technical specifications. Some designs are able to operate with maximum efficiency only in one direction. If you do not take into account this aspect, then after a short period of time the device can be damaged, which involves extra material costs for repairs or the purchase of a new model.

The second aspect that must be considered when choosing - is the environment in which you plan to use a solenoid valve. The technical specifications should be twice the diameter specified: internal and external.

Warning, some foreign manufacturers indicate the information in inches. Most current models are capable of withstanding pressures up to 10B.

Analyzing the domestic market, the greatest demand device Danfoss. Manufacturer presented a whole range of valves:

  1. If you need a model with the flexibility and high reliability, the EVR - the best choice. Line suggesting a direct effect and is suitable for freezing and refrigeration chambers.
  2. EVRA relevant for operation in pipelines with the hot gas.
  3. STF for air conditioning systems capable of maintaining the optimum temperature at any time of the year.

The widespread popularity of Danfoss acquired thanks to the high quality of the goods.

Several recommendations for installation

To install valve previously necessary to prepare a pipeline system, cleaned of dirt and dust to avoid premature failure of the device. Installs a special filter, which helps avoid getting large foreign particles.

Figure 8. installation of the valve

Indicator arrow inscribed on the housing apparatus should be identical to the direction of fluid flow. Otherwise, it can also cause serious damage. Still need the most tightly fasten the ends of the valve. In actual practice, the use of two spanners. Installation is carried out the welding work, or by using compounds that provide for disassembly.

Be sure to isolate the areas where there is a connection. For this goal using sealant or conventional electrical tape. Before you connect the device, it is important to check the specifications of the coils on the requirements.