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Chemical Machinery Equipment: How to Choose Solenoid Core Material

First, the use of
The fluid in the tubing must match that of the medium used in the selected Solenoid Core Material Series model. The temperature of the fluid must be less than the nominal temperature of the core material used for the solenoid valve. Solenoid valve core material allows liquid viscosity is generally below 20EST (Celsius), more than 20EST should be specified. Working pressure difference, the maximum pressure difference in the pipeline is less than 0.04MPa should be used such as ZS, 2W, ZQDF, ZCM series and other direct-acting and step-by-step direct-acting; minimum operating pressure difference is greater than 0.04MPa can be used when the pilot type (pressure Differential type) Solenoid valve core material; the maximum working pressure difference should be less than the maximum calibration pressure of the electromagnetic valve core material; general electromagnetic valve core material is one-way work, so pay attention to whether there is back pressure difference, if there is installation Return valve. If the fluid cleanliness is not high, install a filter in front of the solenoid valve core material. Note the influence of ambient temperature on the magnetic core material of the solenoid valve. The power supply current and power consumption should be selected according to the output capacity. The power supply voltage is generally allowed to be ±10%. The VA (current) value is higher when the AC starts. , General solenoid valve core material requirements for the cleanliness of the media is better. Pay attention to the flow aperture and the nozzle diameter; solenoid valve core material is generally only two control switch; conditions allow to install the bypass pipe, easy to repair; a water hammer phenomenon to customize the electromagnetic valve core material opening and closing time adjustment.
Second, reliability
Solenoid valve core material is divided into normally closed and normally open two kinds; generally used normally closed type, open power, power off; but in the very long open time is very short when closed to use normally open type. Life test, the factory is generally a type test project, to be exact, there is no professional standard for electromagnetic valve iron core material, so choose the electromagnetic valve core material manufacturers carefully. When the operation time is very short, the direct-acting type is generally selected, and the large-caliber selection is used for the fast series.
Third, security
General solenoid valve core material is not waterproof, please use waterproof type when the conditions are not allowed, the factory can be customized. The highest nominal pressure of the solenoid valve core material must exceed the maximum pressure in the pipeline, otherwise the service life will be shortened or other unexpected situations will occur. Corrosive liquids should use all stainless steel SLF) solenoid valve core material. Explosion-proof products must be selected for explosive environments.
Fourth, economy
There are a lot of solenoid valve core materials that can be used for general-purpose solenoid valve core materials. However, the most economical products should be selected based on the above three points.
One: direct-acting solenoid valve core material; there are two types of normally closed and normally open. Normally closed type when the power is off, when the coil is energized, electromagnetic force is generated, so that the moving core overcomes the spring force and the static iron core directly opens the valve and the medium is the passage; when the coil is powered off, the electromagnetic force disappears, and the moving iron disappears. The core is reset under the action of the spring force, and the valve port is closed directly, and the medium is blocked. Simple structure, reliable operation, normal work under zero differential pressure and micro vacuum. Normally open type is just the opposite.
Second, step-by-step direct-action solenoid valve iron core material; The valve is used once to open the valve and the second valve is connected in one, the main valve and the pilot valve step by step to make the electromagnetic force and pressure difference directly open the main valve port. When the coil is energized, an electromagnetic force is generated to cause the moving iron core and the static iron core to pull in. The pilot valve port is opened and the pilot valve port is disposed on the main valve port, and the moving iron core is connected with the main valve core. At this time, the main valve is The pressure of the chamber is unloaded through the pilot valve port, and the main valve core is moved upwards under the influence of the pressure difference and the electromagnetic force to open the main valve medium. When the coil is de-energized, the electromagnetic force disappears. At this moment, the moving iron core closes the pilot valve hole under the action of its own weight and spring force. At this moment, the medium enters the upper cavity of the main valve core in the balance hole, so that the pressure of the upper cavity rises. The main valve is closed under the action of the spring return and pressure, and the medium is shut off. Reasonable structure, reliable operation, and reliable operation at zero differential pressure.
Third, the indirect pilot solenoid valve iron core material; this series of solenoid valve core material is formed by the combination of the pilot valve and the main valve core to form a channel; normally closed type is closed when not powered. When the coil is energized, the generated magnetic force causes the moving iron core and the static iron core to pull in, the pilot valve port opens, and the medium flows toward the outlet. At this time, the pressure in the upper cavity of the main valve plug decreases, which is lower than the pressure on the inlet side, forming a pressure difference against the spring. The resistance moves upwards and reaches the purpose of opening the main valve port, and the medium circulates. When the coil is de-energized, the magnetic force disappears and the moving iron core resets and closes the pilot port under the action of the spring force. At this moment, the medium flows from the balancing hole, the pressure of the upper cavity of the main valve core increases, and the downward movement of the main valve core is caused by the force of the spring. Close the main valve port. The normally open principle is just the opposite. Such as: SLA, DF (φ15 above diameter), ZCZ and so on.
Concerned about the four properties of magnetic valve core material
I. Security:
1. Corrosive media: should choose plastic king electromagnetic valve iron core material and all stainless steel; For strong corrosive media must choose the isolation diaphragm type. Example CD-F.Z3CF. Neutral medium, should also use copper alloy valve shell material for the solenoid valve core material, otherwise, the valve shell often rust off, especially infrequent occasions. Ammonia valves cannot use copper. 2. Explosive environment: must use the appropriate explosion-proof grade products, open installation or dust more occasions should use waterproof, dustproof varieties. 3. The nominal pressure of the solenoid valve core material should exceed the maximum working pressure in the pipe.
II. Applicability:
1. Media characteristics
1.1 Quality gas, liquid state or mixed state Select different types of solenoid valve core materials respectively, for example ZQDF for air, ZQDF-Y for liquid, ZQDF-2 (or -3) for steam, otherwise it will cause malfunction. ZDF series multi-function solenoid valve core material can be connected to gas and liquid. It is best to state the media status at the time of subscription, and it is not necessary to install the user.
1.2 medium temperature products of different specifications, otherwise the coil will burn off, aging of the seals, seriously affecting life expectancy.
1.3 Medium viscosity, usually below 50 cSt. If it exceeds this value, the diameter is larger than 15mm and ZDF series multi-function electromagnetic valve core material is used for special orders. Path is less than 15mm high viscosity solenoid valve core material.
1.4 When the cleanliness of the medium is not high, the recoil filter valve should be installed in front of the core material of the electromagnetic valve. In the case of low pressure, a direct acting diaphragm type electromagnetic valve core material can be used as a CD-P.
1.5 If the medium is directional and does not allow backward flow, ZDF-N and ZQDF-N are required to use two-way flow, please make special requirements.
1.6 medium temperature should be selected within the allowable range of the solenoid valve core material.
2, pipeline parameters
2.1 Select the valve port and model according to the medium flow requirements and the pipe connection method. For example, for a switch from one pipe to two pipes, select CA5 and Z3F for small paths, and select ZDF-Z1/2 for medium or large paths. Another example is to control the convergence of two pipes, please choose ZDF-Z2/1 and so on.
2.2 According to the flow and valve Kv value selected nominal diameter, but also 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 coveted and the price is low.
2.3 Working pressure difference The minimum operating pressure difference is 0,04 Mpa or more. Indirect pilot type is available. The minimum operating pressure difference is close to or less than zero. It must use direct-acting or step-by-step direct type.
3, environmental conditions
3.1 The maximum and minimum temperatures of the environment shall be selected within the allowable range. If there is any excess error, special orders shall be made.
3.2 In the environment with high relative humidity and occasions such as water and rain, waterproof electromagnetic valve core material should be selected
3.3 The environment often has vibrations, bumps and impacts and other occasions should be selected special varieties, such as marine solenoid valve iron core material.
3.4 Use in Corrosive or Explosive Environments
3.5 If the environmental space is limited, please use multi-function solenoid valve core material, because it eliminates the bypass and three manual valves and is easy to repair online.
4, power conditions
4.1 According to the type of power supply, choose AC and DC solenoid valve core materials respectively. In general, AC power is easy to use.
4.2 Voltage specifications Use AC220V, DC24V as much as possible.
4.3 Power Supply Voltage Fluctuation Normally, AC is used for +10%, -15%, and DC is allowed to be ±10%. If there is excess error, it is necessary to adopt voltage regulation measures or make special orders.
4.4 The rated current and power consumption should be selected according to the power supply capacity. It should be noted that the value of VA at the time of AC start is high, and indirect capacity solenoid valve core material should be preferred when capacity is insufficient.
5, control accuracy
5.1 Ordinary electromagnetic valve core material only open and close two positions, in the control of high precision and stable parameter requirements, please use a number of solenoid valve core material; Z3CF three normally open solenoid valve core material, with Wei Qi, Fully open and close three types of traffic;
ZDF-Z1/1 combination multi-function solenoid valve core material has full open, large open, small open, fully open four kinds of flow.
5.2 Operation time: It refers to the time when the electrical signal is turned on or off to the main valve action. Only the core material of the patented product of the company's patented multi-function solenoid valve can adjust the opening and closing time separately, not only meeting the control accuracy requirements, but also preventing water. Hammer damage.
5.3 Leakage The leakage value given on the sample is a common economic grade. If it is too high, please make a special order.
Third, reliability:
1. Work life: This item is not included in the factory test project and it is a type test project. In order to ensure the quality should be selected from the regular manufacturers of brand-name products.
2, the work system: a long-term work system, repeated short-term work and short-term work of three. The company's conventional products are long-term work systems, that is, coils allow long-term power work. For a long time when the valve opens only for a short time, it is better to use the normally open solenoid valve core material. When used in a short-time work system and in large quantities, special orders can be made to reduce power consumption.
3. Operating frequency: When the operating frequency is high, the structure should be made of direct-acting electromagnetic valve iron core material.
4. Operation reliability This test has not been formally included in China's professional standards for iron core materials for electromagnetic valves. In order to ensure quality, it is recommended to select brand-name products from regular manufacturers. In some cases, the number of operations is not large, but the reliability requirements are very high, such as fire protection, emergency protection, etc., must not be taken lightly. Of particular importance, it should also take two consecutive double insurance.
Fourth, economy:
Non-economy is one of the criteria for the selection of funds, energy, and even the waste of life. However, it must be based on safety, application, and reliability. Economics and economics are not only the selling prices of products, but also priority should be given to their function and quality. As well as the cost of installation, maintenance and other accessories, and more importantly, the core cost of an electromagnetic valve core in the entire automatic control system is very low in the entire automatic control system and even in the production line. Damage groups are huge. In short, economics not only refers to the price of a product, but the ratio of the price of a product to the price of a comprehensive product.
Solenoid valve core material failure and exclusion
First, the solenoid valve core material does not work after power
Check the power supply wiring is not bad → re-wiring and connector connection, check the power supply voltage is within ± working range → → normal position range is adjusted, the coil is desoldering → re-welding, coil short-circuit → replace the line working pressure difference is not appropriate → Adjust the pressure difference → or replace the appropriate solenoid valve core material fluid temperature is too high → replace the appropriate solenoid valve core material impurities make the solenoid valve core material of the main valve and moving iron core stuck → cleaning, if any Seal damage should be replaced Seal and filter installed Liquid viscosity is too high, frequency is too high and life has expired → Replace product
Second, the solenoid valve core material can not be closed
The main spool or iron core seal is damaged → replace the seal fluid temperature, viscosity is too high → replace the solenoid valve core material impurities into the solenoid valve core material production valve core or moving iron core → cleaning , The spring life has reached or deformed → Replace, throttle hole balance hole plugging → Clean in time, the working frequency is too high or the service life is up → Reselect product or update product
Third, other conditions
Internal leakage → Check if the seal is damaged, if the spring is not assembled properly. Leakage → Loose connections or defective seals → Tighten screws or replace the seals Noise during power-on → Loose pieces on the head, tighten. The voltage fluctuation is not within the permissible range and the voltage is adjusted. Core suction surface impurities or uneven, timely cleaning or replacement.
Solenoid valve core material and electric valve difference
1. Switch form:
Solenoid valve core material is driven by the coil and can only be turned on or off. The switching time is short. The electric valve is usually driven by a motor. The opening or closing operation requires a certain amount of time for analog measurement and can be adjusted.
2. The nature of work:
Solenoid valve core material generally has a small coefficient of flow, and the working pressure has two effects. The difference is small. For example, the core material flow rate of a general 25-gauge solenoid valve is much smaller than that of a 15-gauge electric ball valve. The solenoid valve core material is driven through the electromagnetic coil and is relatively easily damaged by voltage surges. The equivalent of the switch is to open and close
The electric valve is usually driven by a motor and is relatively resistant to voltage shocks. Solenoid valve iron core material is quick opening and fast closing, generally used in small flow and small pressure, where the switching frequency is large, the electric valve is the opposite. The opening degree of the electric valve can be controlled, and the state is on, off, half-open and half-close, which can control the flow of medium in the pipeline and the electromagnetic valve core material can not meet this requirement. Solenoid valve iron core material can be reset normally, electric valve to such a function need to add reset device.
3 applicable process:
Solenoid valve core material is suitable for some special technical requirements, such as leakage, special fluid media, etc., which are more expensive. Electric valve is generally used for adjustment, but also the amount of switching, such as: fan coil end.

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