The electromagnetic pulse valve belongs to one type of dust removal accessories, and its selection has four principles -- applicability, economy, safety, and reliability.
1. Applicability: Not applicable is equal to waste money on useless things and also bring trouble!
1.1 Medium characteristics
- Different types of solenoid valves should be selected for gaseous, liquid or mixed states respectively. For example, ZQDF is used for air, ZQDF-Y for liquid, and ZQDF-2 (or -3) for steam; otherwise, it may cause malfunction. The ZDF series multi-functional solenoid valve can be used universally for gas and liquid. It's best to specify the medium state when ordering so that the installation user does not need to adjust.
- Medium temperature varies with different specifications of products; otherwise, the coil will burn out and the sealing part will age, which seriously affects the life.
- Medium viscosity is usually below 50cSt. If it exceeds this value, use the ZDF series multi-functional solenoid valve for special orders when the diameter is greater than 15mm. When the diameter is less than 15mm, order high-viscosity solenoid valves.
- When the medium cleanliness is not high, a backflush filter valve should be installed before the solenoid valve. A direct-acting diaphragm solenoid valve can be selected if the pressure is low.
- If the medium is unidirectional and reverse flow is not allowed, single-directional ZDF-N and ZQDF-N solenoid valves are required. If bidirectional flow is needed, please make a special request.
- The medium temperature should be selected within the allowable range of the solenoid valve.
2. Pipeline parameters
- Select the valve bore and model according to the medium flow direction requirements and pipeline connection method.
- Select the nominal bore based on the flow and valve Kv value, or select the same as the pipeline inner diameter.
- Working pressure difference: If the minimum working pressure difference is above 0.04Mpa, an indirect pilot type can be selected; if the minimum working pressure difference is close to or less than zero, a direct-acting or step-by-step direct-acting solenoid valve must be selected.
3. Environmental conditions
- The highest and lowest environmental temperatures should be selected within the allowable range. If there is a deviation, a special order should be made.
- In environments with high relative humidity and water droplets/rain, waterproof solenoid valves should be selected.
- In environments with frequent vibration, shaking, and impact, special varieties should be selected, such as marine solenoid valves.
- In corrosive or explosive environments, priority should be given to selecting corrosion-resistant solenoid valves based on safety requirements.
- If the environmental space is restricted, multi-functional solenoid valves should be selected because they eliminate the need for bypasses and three manual valves and facilitate online maintenance.
4. Power supply conditions
- According to the type of power supply, AC and DC solenoid valves should be selected respectively. Generally speaking, AC power is convenient to obtain.
- Voltage specifications should preferably select AC220V.DC24V.
- Power voltage fluctuations: Normally, AC selects +%10%.-15%, and DC allows ±%10 around. If there is a deviation, stabilization measures must be taken or a special order requirement should be proposed.
- Rated current and power consumption should be selected according to the power capacity. Note that VA value is higher during AC startup; in cases where capacity is insufficient, indirect-conducting solenoid valves should be prioritized.
5. Control accuracy
- Ordinary solenoid valves only have two positions: open and closed. When high control accuracy and parameter stability are required, multi-position solenoid valves should be selected; Z3CF three-position normally open solenoid valves have three flow rates: micro-open, fully open, and closed; ZDF-Z1/1 combination multi-functional solenoid valves have four flow rates: fully open, largely open, slightly open, and fully open.
- Action time refers to the time from the connection or disconnection of the electrical signal to the completion of the main valve action. Only our company's patented product, the multi-functional solenoid valve, can separately adjust the opening and closing times, which not only meets the control accuracy requirements but also prevents water hammer damage.
- Leakage volume: The leakage volume values given in the sample are commonly used economic grades. If it seems too high, a special order should be made.
2. Economy: Not being economical is a waste of funds, energy, and even lives.
- One of the criteria for its selection, but must be on the basis of safety, applicability, and reliability.
- Economy is not just the price of the product, but more importantly, consider its function and quality, as well as the costs of installation, maintenance, and other attachments.
- More importantly, the cost of a solenoid valve in the entire self-control system or production line is negligible. If you choose a cheap one and make a mistake, the resulting damage could be enormous. In short, economy is not just about product price, but rather the performance-price ratio and comprehensive cost-price ratio.
3. Safety: Neglecting safety will lead to disasters!
- Corrosive media: Plastic King solenoid valves and all stainless steel ones are suitable. For strongly corrosive media, isolation membrane types must be selected. Neutral media are also suitable for copper alloy valve shell material solenoid valves, otherwise, rust chips often fall off in the valve shell, especially in infrequent action situations. Ammonia valves cannot use copper materials.
- Explosive environment: Corresponding explosion-proof grade products must be selected. For outdoor installation or dusty occasions, waterproof and dustproof varieties should be selected.
- The nominal pressure of the pulse solenoid valve should exceed the maximum working pressure inside the pipe.
4. Reliability: Unreliability will harm the entire system!
- Service life: This item is not included in the factory test project, it belongs to the type test project. To ensure quality, branded products from regular manufacturers should be selected.
- Working mode: Divided into long-term work mode, repeated short-time work mode, and short-time work mode. For situations where the valve is open for a long time and only closed for a short time, normally open solenoid valves should be selected. For short-time work mode with large batches, special orders can be made to reduce power consumption.
- Working frequency: When high action frequency is required, the structure should preferentially select direct-acting solenoid valves, and the power source should preferentially select AC.
- Action reliability: Strictly speaking, this test has not yet been officially included in China's solenoid valve professional standard. To ensure quality, branded products from regular manufacturers should be selected. In some situations, the number of actions is not many, but the reliability requirement is very high, such as fire protection, emergency protection, etc., and must not be taken lightly. Especially important ones should adopt dual insurance by using two connected ones.