The selection of solenoid valves should follow the four principles of safety, reliability, applicability, and economy in sequence, as well as six on-site operating conditions requirements (i.e. diameter size, medium type, pressure level, power supply voltage, action mode, and special functions).

Selection criteria

1、 Select the solenoid valve based on the type of medium: valve body material, sealing material, temperature

1. Corrosive fluid: The valve body material should be stainless steel or PTFE (polytetrafluoroethylene, commonly known as plastic king), and fluororubber or PTFE sealing materials should be selected.

2. Edible or ultra clean fluid: The valve body material should be selected from sanitary grade stainless steel, and silicone rubber sealing material should be selected.

3. High temperature fluid: It is necessary to choose solenoid valves made of high-temperature resistant stainless steel materials and sealing materials, and to choose piston type principle structures.

4. Fluid state: ranging from gaseous, liquid, or mixed state, especially when the mouth is large, it must be distinguished because it is related to the parameters of the guide hole.

5. Fluid viscosity: Usually below 50cSt, it can be freely selected. If it exceeds this value, a high viscosity solenoid valve should be used.

6. Fluid cleanliness: When the medium contains impurities, install a filter in front of the solenoid valve and choose other structures.

2、 Selection of solenoid valve based on pressure level: principle, structure, and type

1. Nominal pressure: This parameter has the same meaning as other general valves and is determined based on the nominal pressure of the pipeline or 1.5 times the operating pressure.

2. Working pressure: refers to the value obtained by subtracting the pressure in the pipeline at the back end of the valve from the pressure in the pipeline at the front end of the valve when the solenoid valve is in the closed state; When there is no pressure difference, low pressure difference, or vacuum, the direct acting or distributed direct acting principle must be selected, but the diameter of the direct acting principle cannot be too large; When there is a certain pressure difference or above, choose the pilot principle structure. Our company's pilot piston structure solenoid valve can operate with a working pressure difference of only 0.01MPa.

3、 Divided into various types based on the temperature of the medium:

Our factory produces eight types of solenoid valves, including normal temperature (0-60 ℃), medium temperature (0-120 ℃), high temperature (0-200C ℃), ultra-high temperature (0-250 ℃), (0-300 ℃), low temperature (-50~60 ℃), and ultra-low temperature (-200~60 ℃).

4、 Select the solenoid valve based on pipeline parameters: diameter specification (i.e. DN), interface method (connection method)

1. Determine the diameter (DN) size according to the on-site pipeline inner diameter size or flow requirements.

2. Interface method: Generally, for DN>65, flange interface should be selected, while for DN ≤ 65, threaded or flange interface can be freely selected according to user needs.

5、 Power supply voltage selection:

Various AC and DC voltages, such as AC24V AC36V、AC127V、AC220V、AC380V。DC12V、DC24V、DC36V、DC72V、DC110V、DC220V。

But usually, AC220V and DC24V are preferred.

6、 Choose control mode based on working hours or special needs: normally closed, normally open, self holding, emergency cut-off (manual reset)

1. When the solenoid valve needs to be started for a long time and the continuous opening time greatly exceeds the closing time, it is advisable to choose a normally open type.

2. If the switch between opening and closing is frequent or the opening time is short, or the opening and closing time is similar, then choose the normally closed type.

3. However, for some working conditions used for safety protection, such as furnace flame monitoring, gas leakage alarm, and fire safety linkage system, emergency cut-off solenoid valves should be selected instead of long-term electrification (long-term electrification is only a relative concept), and normally open type should not be selected.

4. Self holding solenoid valve (also known as bistable) is a new technology mainly used in situations where energy conservation or low-voltage driving are required.

7、 Select auxiliary functions according to environmental requirements: explosion-proof, check, manual, waterproof fog, water shower, diving

1. Flammable and explosive environments: corresponding levels of explosion-proof solenoid valves must be selected (our company's product explosion-proof mark: EXD Ⅱ CT5)

2. When there is a backflow phenomenon in the pipeline medium, you can choose our company's solenoid valve with check function.

3. When on-site manual operation of the solenoid valve is required, you can choose our company's solenoid valve with manual function.

4. Waterproof and dustproof varieties (with a protection level of IP45 or above) should be selected for outdoor installation or in dusty environments. Submersible solenoid valves (with a protection level of IP68 or above) must be used for fountains or underwater pipelines.