Solenoid valve principle, selection, routine maintenance, super detailed!
Fountain Equipments

Solenoid valve principle, selection, routine maintenance, super detailed!

Item No.: XYHDCF1001
so far, the solenoid valve at home and abroad from the principle is divided into three categories (ie: direct-acting, step-by-step direct, pilot), and from the valve structure and materials The difference between the principle and the principle is divided
First, the principle of solenoid valve

The history of the development of the solenoid valve, so far, the solenoid valve at home and abroad from the principle is divided into three categories (ie: direct-acting, step-by-step direct, pilot), and from the valve structure and materials The difference between the principle and the principle is divided into six sub-categories (direct-acting diaphragm structure, step-by-step diaphragm structure, pilot-type diaphragm structure, direct-acting piston structure, step-by-step piston structure, pilot piston structure).

1. Direct-acting solenoid valve

Principle: power, the electromagnetic coil to produce electromagnetic force to lift the closure from the valve seat, the valve open; power, the electromagnetic force disappears, the spring force to close the valve on the valve seat, the valve closed.

Features: in the vacuum, negative pressure, zero pressure can work properly, but the general diameter of not more than 25mm.

3. Pilot solenoid valve

Principle: When the electromagnetic force, the electromagnetic force to open the pilot hole, the upper chamber pressure drops rapidly in the closure around the formation of low pressure on the formation of high, pushing the closure to move up, the valve open; power, the spring force to the pilot hole closed , The inlet pressure through the bypass hole quickly into the upper chamber around the valve around the formation of low pressure on the lower, pushing the closure down, close the valve.

Features: The upper limit of the fluid pressure range is high, but the fluid pressure differential condition must be met.

Second, the installation instructions

1. Read the product manual carefully before installation, check whether the product meets the requirements, remember the installation points, and prepare for it.

2. Proof of the nameplate and the parameters of the choose product is consistent.

3. Before taking over with the pressure of 0.3MPa on the pipeline, the pipe in the metal powder and sealing material residues, rust and so on.

4. Note that the cleanliness of the media, if the media mixed with dirt, impurities and other obstacles to the normal operation of the solenoid valve, the pipeline should be installed filter valve.

5. Solenoid valve should not be installed in the pipeline concave, installed in the container discharge pipe, pay attention not from the bottom of the container leads, but should be installed in the bottom of the container slightly above the position.

6. If the media will be the phenomenon of water hammer, then you should use the function of a waterproof hammer valve or take appropriate precautions.

7. Steam solenoid valve inlet side should be equipped with a trap, where the nozzle should be tilted.

8. Solenoid valve is generally adapted, can not be installed, usually in the valve body with "→" that the flow direction of the media, the installation should be in accordance with the "→" direction to install.

9. General solenoid valve parts of the electromagnetic coil should be vertical up, perpendicular to the pipeline, some products are specified, please follow the instructions to install.

10. Take care that the sealing material can not be used in excess. If the thread is connected, the thread should be kept within the effective length and wrinkled with the rasp at the end of the half-pitch, and the sealing tape will be wound from the end of the tooth. Otherwise, the excess sealing tape or adhesive will enter the electromagnetic The inner cavity of the valve, and the occurrence of an accident that hinders normal operation.

11. The installation of the solenoid valve should have some reserved space for daily maintenance and regular maintenance.

12. Install the violence or pipe clamp with a fixed body, and then screw on the tube, do not force the role of the electromagnetic coil components caused by deformation, so that the solenoid valve is difficult to work properly.

13. In the case of insufficient pipe or water hammer, please fix the valve with the bracket.

14. When used in a frozen place, the pipe shall be protected with a heat insulating material or a heater shall be provided on the pipe.

15. To confirm, the solenoid valve itself and its connection with the nozzle is leaked.

16. The connection of the coil lead wire should be checked, especially the three lead wires.

17. Electrical components connected to the solenoid valve, such as relays, switches and contactors. When opening the valve should not vibrate, otherwise the work will be unreliable, and affect the life of the solenoid valve.

18. Electrical circuit to access the appropriate insurance line, as the electrical circuit protection.

Third, the selection of essentials

Solenoid valve selection should first follow the safety, reliability, applicability, economy of the four principles, followed by six aspects of the field conditions (ie, pipeline parameters, fluid parameters, pressure parameters, electrical parameters, Special requirements to choose).

Selection basis:

1. According to the pipeline parameters to select the solenoid valve diameter specifications (ie DN) and interface mode

(1) Determine the diameter (DN) size according to the size of the pipe pipe diameter or flow rate.

(2) interface, general> DN50 to select the flange interface, ≤ DN50 can be freely choose according to user needs.

2. Select the material and temperature group of the solenoid valve according to the fluid parameters

(1) corrosive fluid: should use corrosion-resistant solenoid valve and all stainless steel; edible clean fluid: should use food grade stainless steel solenoid valve.

(2) high temperature fluid: to choose the use of high temperature electrical materials and sealing materials made of solenoid valve, but also to choose the type of piston structure.

(3) fluid state: large to have a gaseous, liquid or mixed state, especially when the diameter is greater than DN25 order must be distinguished.

(4) fluid viscosity: usually below 50cSt can be arbitrarily choose, if more than this value, you should use high viscosity solenoid valve.

3. According to the pressure parameter selection solenoid valve principle and structure varieties

(1) Nominal pressure: This parameter is the same as the meaning of other general-purpose valves, according to the pipeline nominal pressure to set.

(2) working pressure: If the working pressure is low must use the principle of direct-acting or step-by-step direct; the Lowest working pressure of 0.04Mpa above the direct-acting, step-by-step direct, pilot can be used. "

4. Electrical selection: voltage specifications should be preferred to use AC220V, DC24 more convenient.

5. According to the length of continuous working hours to choose: normally closed, normally open, or sustainable power

(1) When the solenoid valve takes a long time to open, and the duration of the excess time should be used to open normally open type.

(2) If the open time is short or open and off the time is not much, then select the normally closed type.

(3) However, some of the conditions for security protection, such as furnace, kiln flame monitoring, you can not choose normally open, should be choose long-term power type.

6. According to environmental requirements to select auxiliary functions: explosion, stop, manual, waterproof mist, water shower, diving

(1) Explosive environment: must use the corresponding explosion-proof grade solenoid valve.

(2) when the tube fluid back flow phenomenon, you can choose with a return function solenoid valve.

(3) When the need for manual operation of the solenoid valve, you can choose with manual function solenoid valve.

(4) open-air installation or dust occasions should use waterproof, dust-proof varieties (protection level above IP54).

(5) For fountains must use submersible solenoid valve (protection class above IP68).

Fourth, routine maintenance methods

1. It is recommended that the use of units assigned to the person responsible for, use and maintenance.

2. 1-2 times a year regular maintenance is the solenoid valve reliable work and longevity of the best way. The following four kinds of cases inside the solenoid valve are the reasons that prevent the solenoid valve from working properly and shortening the life.

(1) changes in the use of the media medium;

(2) take over the rust;

(3) air compressor oil oxidation, resulting in carbon particles such as debris tar, mixed into the pipeline;

(4) pipe dust and other impurities.

3. After the installation of the solenoid valve or after a long time after the re-put into operation, must pass the media test action several times, working properly before the official use.

4. steam valve for a long time after the re-put into operation, should be drained after the test water several times, the normal work before putting into operation.

5. Before servicing and maintenance, the power must be switched off and the media pressure removed.

6. Solenoid valve coil assembly should not be opened.

7. Open the solenoid valve cleaning, you can use kerosene, trichlorethylene and other solutions, but should be noted that rubber parts may be soaring, so to replace the rubber pieces.

8. Disassemble the cleaning, the parts should be placed in order to resume installation.

5, common faults and treatment methods

1. power does not move

Cause Analysis: Poor power supply wiring; power supply voltage is not within the allowable range; coil short circuit or burn out.

Treatment: connect the power cord; adjust the voltage within the normal range; replace the coil.

2. The fluid can not pass through the valve

Cause: fluid pressure or working pressure does not meet; fluid viscosity or temperature does not meet; spool and moving core around the mixed fouling, impurities; valve before the filter or guide hole plug; use the work frequency is too high or life maturity.

Treatment: adjust the pressure or work pressure or replace the appropriate product; replace the appropriate product; the internal cleaning, the valve must be installed before the filter; timely cleaning filter or guide valve hole; re-election product model or replacement of new products.

3. When the valve is closed, the fluid can not be cut off

Symptom: fluid viscosity does not meet; fluid temperature does not meet; spring deformation or life expires; seat defective or sticky stolen goods; gasket out, defect or deformation; balance hole or throttle block; High or life expires.

Treatment, replacement of the appropriate product; replacement of the appropriate product; plus gasket or replace the spring; cleaning, grinding or update; update, re-assembly; timely cleaning; re-election product model or change the new product.

4. Exposure

Cause Analysis: pipe connection loose; pipe connection outside the seal damage.

Remedy: Tighten the bolts or take over the threads; replace the seals.

5. Internal leakage is serious

Cause: fluid temperature does not meet; guide valve seat and the main valve seat with impurities or defects; pilot valve and the main valve gasket out or deformation; spring assembly is poor, deformation or life expires; use the work frequency is too high.

Treatment method: adjust the fluid temperature or replace; if there is cleaning or grinding repair or replacement; replace the gasket; replace the spring; re-election product model or replace the new product.

6. When the power is too loud

Reason analysis: fasteners loose; voltage fluctuations, not within the allowable range; fluid pressure or working pressure is not suitable; fluid viscosity does not meet; armature suction surface with impurities.

Treatment: tighten; adjust to the normal range; adjust the pressure or work pressure or replace the product; replace the appropriate product; timely cleaning.