First, security: do not pay attention to safety that will have a disaster! Corrosive media: the choice of plastic valve solenoid valve and stainless steel; for the corrosive medium must use isolation diaphragm. Example CD-F.Z3CF. Neutral medium, copper alloy should also be used as the valve material of the solenoid valve, otherwise, the valve shell often rust off, especially when the action is not frequent. Ammonia valves can not use copper. Explosive environment: you must choose the appropriate level of explosion-proof products, open-air installation or dust should be more occasions use waterproof, dustproof varieties. The nominal pressure of the solenoid valve should exceed the maximum working pressure in the pipe. Second, the applicability: Does not apply to spend money to buy goods, but also trouble! 1. Dielectric Characteristics 1.1 Solenoid valves of different types are selected for gas, liquid or mixed state. For example, ZQDF is used for air, ZQDF-Y is used for liquid and ZQDF-2 (or -3) is used for steam. Otherwise, it may cause malfunction . ZDF series of multi-function solenoid valve is available in the gas. Liquid. The best time to state the media state, the installation users do not have to adjust. 1.2 different medium temperature product specifications, or the coil will burn, seal aging, seriously affect the life of life. 1.3 Medium viscosity, usually below 50cSt. If more than this value, diameter greater than 15mm with ZDF series of multi-function solenoid valve for special order. Path less than 15mm set high viscosity solenoid valve. 1.4 Media cleanliness should be equipped with a recoil filter valve in front of the solenoid valve, the pressure is low fashion can choose direct acting diaphragm solenoid valve for example CD-P. 1.5 If the medium is directional and does not allow backflow ZDF-N and ZQDF-N need to be used in both directions, please make a special request. 1.6 medium temperature should be selected within the allowable range of the solenoid valve. 2.Pipeline parameters 2.1 According to the media flow requirements and pipe connections choose the valve port and model. For example, the small diameter selection CA5 and Z3F for one pipe to two pipes, ZDF-Z1 / 2 for medium or large diameters. Another example is the control of the convergence of two pipelines, please choose ZDF-Z2 / 1. 2.2 According to the flow and the valve Kv value selected nominal diameter, but also optional with the pipe diameter. Please note that some manufacturers are not marked with Kv value, often the size of the valve hole is smaller than the interface diameter, must not be greedy price low and misleading. 2.3 working pressure minimum working pressure differential above 0.04Mpa is optional indirect pilot; minimum working pressure close to or less than zero must be used direct or step-by-step direct type. 3. Environmental conditions 3.1 The maximum and minimum temperature of the environment should be selected within the allowable range, if there is any need for special order made over. 3.2 Ambient high relative humidity and rain drops and other occasions, the election should be waterproof solenoid valve. 3.3 The environment often vibration, bump and impact occasions should choose a special variety, such as marine electromagnetic valve. 3.4 In a corrosive or explosive environment should give priority to the use of corrosion-resistant selection of safety requirements. 3.5 If the environmental space is limited, please use multi-function solenoid valve, because it eliminates the need for bypass and three manual valves and easy on-line maintenance. 4. Power Conditions 4.1 According to the type of power supply, were selected AC and DC solenoid valve. In general AC power access convenience. 4.2 voltage specifications exhausted preferred AC220V.DC24V. 4.3 Power supply voltage fluctuations are usually used in the exchange of +% 10% .- 15%, DC allows ±% 10 or so, if ultra poor, to take measures to stabilize the voltage or make special order requirements. 4.4 should be selected according to the power capacity of the rated current and power consumption. Should pay attention to AC starting VA value is higher, in the lack of capacity should be preferred indirect induction solenoid valve. 5. Control accuracy 5.1 Ordinary solenoid valve only open and close two positions, high precision control parameters and parameters require stable multi-position solenoid valve; Z3CF three normally open solenoid valve, with micro-Kai, fully open and closed three Kinds of flow; ZDF-Z1 / 1 combination of multi-function solenoid valve with full open, big open, small open, full open four flow. 5.2 Operating time: refers to the electrical signal is turned on or off to the completion of the main valve action time, only the company's patented multi-function solenoid valve can be opened and closed separately adjusted, not only to meet the control accuracy requirements, but also to prevent water hammer damage. 5.3 Leakage The sample given on the value of leakage for the commonly used economic level, if too high, please make a special order. Third, the reliability: unreliable will damage the entire system! Working life, this is not included in the factory test project, a type test project. In order to ensure the quality of regular manufacturers should be selected brand-name products. Working standard: sub-long-term working system, repeated short-term working system and short-term working system three. The Company's conventional products are long-term working system, that is, the coil allows long-term power work. For a long time to open the valve only a short time off, it should be used normally open solenoid valve. Used in short-time working system and the volume is very large, special orders can be made to reduce power consumption. Operating frequency: high operating frequency requirements, the structure should be preferred direct-acting solenoid valve, the power to listen to the preferred exchange. Action reliability: Strictly speaking, this test has not yet officially included in the professional standards of our solenoid valve, to ensure the quality of the regular manufacturers should choose the brand-name products. In some occasions, the number of actions is not much, but the reliability requirements are very high, such as fire protection, emergency protection, must not be taken lightly. Particularly important, you should also take two double insurance. Economies: Ineconomy is one of the criteria used for the waste of capital, energy and even life, but it must be based on a safe, applicable and reliable economy. Economy is not only the selling price of the product, but also the priority given to its function and quality as well as the cost of installing maintenance and other accessories. More importantly, the cost of a solenoid valve in the entire automatic control system in the entire automatic control system and the production line is minimal, if you seek a cheap and missed the early damage caused by the group is huge. In short, economy refers not only to the product price, but to the product's cost performance to price ratio.