(3) Simplified valve structure and process The solenoid valve is an automatic control valve that is simple in principle and structure, but further simplified. The solenoid valve of the washing machine and refrigerator in the household appliance industry, the structure and process of its components are suitable for mass production. Ordinary solenoid valve coil components have been packaged in plastic to reduce the breakage of the lead wire, and at the same time easy to achieve waterproof, explosion-proof and other protection requirements. Valve body, valve cover and other components have been precision casting, forging and other processes, engineering plastic solenoid valves have also been on the market. Domestic explosion-proof solenoid valves are not only explosion-proof, but also encapsulated and intrinsically safe. High pressure and high temperature solenoid valves have also appeared to simplify the structure and process. Dual Battery Manager,Smart Car Dual Battery Manager,Dual Battery Isolator,In-Vehicle Dual Battery Chargers SUZHOU DEVELPOWER ENERGY EQUIPMENT CO.,LTD , https://www.fisoph-power.com
2.2. Development in the direction of intelligence This mainly refers to how the solenoid valve can better cooperate with the smart meter to improve the control precision and reliability of the system. It is generally considered that the position adjustment is difficult to achieve high precision. However, in many fields, the appropriate method can achieve the required high precision, which greatly saves the cost and more solenoid valve technology.
(1) Double combined solenoid valve. This is a combination of solenoid valves of different sizes. The fuel dispensers that are used in large quantities have a metering accuracy of up to 0.02%, and both use double solenoid valves. The large valve is opened, so that the refueling is nearly completed in a short time; then the large valve is closed, and the small valve is supplemented to ensure the flow accuracy. This technology has been applied abroad for many years, and its products are manufactured by ASCO Honeywell, a world-renowned solenoid valve specialist. Now the company's production of double solenoid valves has reached the index of imported products, as well as unique performance. By the way, it is pointed out that the measurement of large-scale flow of domestic oil depots is still introducing or replicating foreign multi-stage shut-off valves with complicated structure and unstable performance. This product is not made by world-famous professional companies because the market demand is not enough to attract them. interest. In fact, our oil depot uses a large-flow dual-combination valve produced domestically, and the effect will be much better. Double combination valves are also commonly used to control parameters such as temperature, pressure, and liquid level. The large valve guarantees the basic amount and the small valve provides the compensation amount. In systems where the parameters are relatively stable, this positional control can be quite accurate. For systems with large parameter changes, the rate of change is still subject to certain constraints, such as temperature control systems, which are still affected by thermal inertia. Therefore, the properly used double combined valve can greatly reduce the cost relative to the regulating valve under the premise of meeting the control requirements.
(2) Three-position solenoid valve and digital valve Three-position solenoid valve has three working positions, usually not energized, in the micro-start state, the valve provides initial flow; gives an electric signal, the solenoid valve is fully open, providing large flow For another electrical signal, the valve closes. FESTO solenoid valves are divided into several categories during operation, FESTO solenoid valves
The solenoid valve is magnetically attracted by the electromagnetic coil to overcome the pressure of the spring to drive the spool, and the electromagnetic coil has a simple structure and a low price, and can only realize the switch;
The electric valve drives the valve stem through the motor to drive the spool, and the electric valve is divided into (shut-off valve) and regulating valve. The shut-off valve is a two-position operation that is fully open and fully closed. The regulating valve is equipped with an electric valve positioner on the above, and the valve is dynamically stabilized in one position by closed loop adjustment.
Comparison of the use of electric and solenoid valves:
Solenoid valve: Switch control for liquid and gas lines, is a two-DO control. Generally used for the control of small pipes.
Electric valve: Analog adjustment for pipe media flow in liquid, gas and wind systems, is AI control. In the control of large valves and wind systems, electric valves can also be used for two-position switch control.
Solenoid valve: can only be used as a switch quantity, is DO control, can only be used for small pipe control, common in DN50 and below pipes.
Electric valve: It can have AI feedback signal, which can be controlled by DO or AO. It is more common in large pipes and dampers. [1]
1, switch form:
The solenoid valve is driven by the coil and can only be turned on or off. The switching time is short.
The drive of the electric valve is generally driven by a motor. It takes a certain amount of time to simulate the opening or closing action, and can be adjusted.
2. Nature of work:
Solenoid valves generally have a small flow coefficient and a small difference in working pressure. For example, a general 25-caliber solenoid valve has a smaller flow coefficient than a 15-caliber electric ball valve. The solenoid valve is driven by an electromagnetic coil and is relatively easily damaged by voltage surges. Equivalent to the role of the switch, is the role of opening and closing.
The drive of the electric valve is generally a motor, which is more resistant to voltage shock. The solenoid valve is fast open and fast closed. It is generally used in small flow and small pressure, and the electric switch is required in the place where the switching frequency is large. The opening of the electric valve can be controlled. The state has open, closed, half open and half closed, which can control the flow of the medium in the pipeline and the solenoid valve can not meet this requirement.
Solenoid valves can be reset by general power failure. For such functions, electric valves require a reset device. [2]
3. Applicable technology:
Solenoid valves are suitable for some special process requirements, such as leakage, special fluid media, etc., which are more expensive.
Electric valves are generally used for adjustment and also have a switching quantity, such as: fan coil end.
FESTO solenoid valve is divided into several categories when operating
FESTO solenoid valves are also equipped with two tees 4 and unions. 6. This piping system takes up a lot of space and is time consuming to install and leaks easily. The ZDF series of multi-function solenoid valves have been awarded the Geneva International New Technology Gold Award for the ingenious elimination of these additional accessories. A filter is required on the front of the automatic control valve. The use of multiple self-control valves also often requires the installation of check valves to prevent interference between the pipes. One-way solenoid valves, combination solenoid valves, and solenoid valves with filtration have now played a role in simplifying piping.