About solenoid valve technology development
1、The streamlined direction development is precisious and simple. only a simple long-lasting circulation. This is also the permanent pursuit for scientists and engineers.
（1）Simplify control circuit past actuators uses extensive pneumatic and electrical control circuit, which increases the complexity of the system, while the pilot-type solenoid valve forms to use of media its own control loop, the structure is very simple. over the past number of technical parameters of solenoid valve both at home and abroad is also restricted, and now the domestic solenoid valve diameter has been extended to 300mm; medium temperature as low as - 200 ℃, up to 450 ℃; working pressure from vacuum to 25MPa. Action time from ten seconds to a few milliseconds. New developments in these technologies has been completely replace the original bulky and expensive of the two position control fast shut-off valves and pneumatic valves, electric valves, can also partially replace adjustable pneumatic and electric control valve. (How can we meet the regulation accuracy requirements better, also described following). Foreign textile, light industry, urban construction industry have a large number of replacing solenoid valve, while the metallurgical, chemical and other industries took the lead in the auxiliary systems are used in an increasing number of solenoid valves.
（2）simplify Pipeline system automatic control valve must equip with some auxiliary valves and pipe fittings in the pipe. For example, bypass isolation shown in Figure 1 is a typical installation method shall be equipped with three manual valves, of which manual valve 1 is the bypass valve, manual backup. The manual valves 2 and 3 are the isolation valve, to ensure that on-line maintenance of automatic control valves 5. Of course, have to equip with two three-way 4, and joints 6. This pipeline system occupied a large space, installation and time-consuming, but also prone to leaks. ZDF Series multi-functional solenoid valve cleverly eliminating the need for these external attachment, but still have isolated bypass feature, which won the Gold Medal at the Geneva International of new technologies. in front of Automatic control valves should be installed filters. Joint use of multiple automatic control valve is often required to install one-way valves to prevent interference between channels. Now, one-way solenoid valve, combined solenoid valve and solenoid valves with filter have played an important role in streamlining pipeline.
（3）simplify structure and process solenoid valves belong to principles and structures are simple and automatic control valves, but should be further simplified. Household appliances, washing machines, refrigerators are equipped with solenoid valves, its parts and components structure and process are suitable for mass production. General solenoid valve coil parts has adopted plastic package to reduce the pinout of the fault rupture, meanwhile easy to implement water-proof, explosion-proof and other protection requirements. Valve body, bonnet and other components had been used in precision casting, forging, etc. technology, engineering plastic solenoid valve has also been available in volume. At home Explosion-proof solenoid valves has not only explosion-proof, as well as pouring seal type, intrinsically safe. High pressure and high temperature solenoid valves have emerged to simplify the structure and process.
2、Intelligent direction development mainly refers to the solenoid valve how to co-ordination with the smart meters better, and to improve the system of control precision and reliability. generally believed that bit-style regulation is very difficult to achieve high precision, but in many occasions, you can use an appropriate manner to achieve the required very high accuracy, while saving the cost mostly.
（1）Double combined solenoid valve. This is a different size of solenoid valves put in together. Large use of the measurement accuracy of oil tankers is up to 0.02%, have adopted double-solenoid valve. Large valve opens, allowing fuel in a relatively short period of time to near completion; and then close the large valve, from a small valve to ensure flow of additional accuracy. This technology has been applied abroad for many years, products from the world's leading professional company ASCOHoneywell such as solenoid valves manufactured. Now, our company has achieved double-solenoid valve indicators of imported products, as well as a unique performance. Note in passing that the measurement of large flow of domestic oil tanks are still abroad, the structure of the introduction or imitation is more complex due to stable performance, multi-segment off valve, this product is not the world's leading professional company system, because the market demand is not enough to be cited in their interest. In fact, we use the domestic production of oil tanks, the double combined high flow valve, the effect would be much better. Double combined valve is also commonly used to control the temperature, pressure, liquid level and other parameters. Large valves ensure that the basis of the amount of compensation for the amount of small valves. Relative stability in the parameter system, this digital-type control can achieve very high accuracy. the system parameters change greatly, the rate of change still with certain restrictions, such as temperature control system, is still under heat inertia effects. Therefore, the use of appropriate combined double-valve control requirements reduce costs to meet the controling requirements prerequisites compared with the control valve.
（2）Three-position solenoid valves and digital valve three-position solenoid valve spool has three working positions, they were not in power, in the low lift state, the valve provides an initial flow; to give an electrical signal, solenoid valve fully open, providing large flow; to give another kinds of electrical signals, the valve closed.
The valve also has a manual device, making long-off valves without need power. Three-position solenoid valve can be considered as a structure more compact double-solenoid valve, it is very easy to achieve the three-position regulation, has received a lot of applications. ZDF Multi-funtional solenoid valve further idea is that a certain proportion of n-size solenoid valve into the composition of 2n kinds of flows, similar to the digital circuit, it is said this combined valve as the digital valve. In fact two different sizes of double-valve or three-position valves can produce 24=16 or 32 = 9 kinds of flows, has been able to reach very high accuracy. In principle, it is said that it has the advantage of supporting industrial control computer, but because applications have not yet made a lot of demand, the technology is still in the testing stage.
（3）Self-holding type solenoid valve is solenoid valve only moments power on to complete the valve switching action without electricity to keep the spool position. It has the advantage of saving energy, in particular in the occasion of using batteries as power supply, and may without to consider the temperature rise, thus the coil has long life, at high temperature, explosion-proof and other occasions have a higher security. Common are mechanical maintenance and permanent magnet to maintain, but also double-coil and single coil, single coil magnetic maintain structure is the most simple. It is based on changing the polarity of DC power to change the two states of corresponding valve switches. This solenoid valve coil external wiring is required to install a separate switch, and with intelligent instrument package will be very convenient. IC Card Pre-pay gas and water meters are equipped with solenoid valve are one key to success, in which the self-sustaining technology is an important factor in the success. the domestic self-sustaining solenoid valve has become increasingly mature, our company has provided supports to a multi-smart factories.
3、The gerenal direction development solenoid valves are on a wide range of applications, while the situation is vastly different when used. Enhance performance can reduce the manufacturing, purchasing, storage, installation, maintenance costs, in recent years made great strides in this regard.
（1）response time is adjustable to give electrical signal to the spool moves to complete the time known as the response time. Want to switch at different speeds on different occasions, there are four combinations: fast opening fast off ---- for the rapid response system; fast open slow off ---- is used to prevent water hammer; slow open fast off --- for the slow open and emergency break; slow open slow off -----for a smooth transition. ZDF Multi-functional solenoid valve can adjust either state easily, the application is very flexible.
