The selection of solenoid valves should first follow the four principles of safety, reliability, applicability, and economy, and secondly, according to the six aspects of on-site working conditions (ie, pipeline parameters, fluid parameters, pressure parameters, electrical parameters, action mode, special request for selection).
Selection basis:
1. Select the solenoid valve according to the pipeline parameters: diameter specification (ie DN), interface mode
1) Determine the diameter (DN) size according to the inner diameter size or flow requirements of the on-site pipeline;
2) Interface mode, generally > DN50 should choose flange interface, ≤ DN50 can be freely selected according to user needs.
2. Select the solenoid valve according to the fluid parameters: material, temperature group
1) Corrosive fluids: corrosion-resistant solenoid valves and all stainless steel should be used; edible ultra-clean fluids: food-grade stainless steel solenoid valves should be used;
2) High-temperature fluid: Choose a solenoid valve made of high-temperature-resistant electrical materials and sealing materials, and choose a piston-type structure;
3) Fluid state: as large as gaseous state, liquid state or mixed state, especially when the caliber is larger than DN25, it must be distinguished;
4) Fluid viscosity: Usually, it can be selected arbitrarily below 50cSt. If it exceeds this value, a high-viscosity solenoid valve should be selected.
3. Select the solenoid valve according to the pressure parameters: principle and structure variety
1) Nominal pressure: This parameter has the same meaning as other general valves, and is determined according to the nominal pressure of the pipeline;
2) Working pressure: If the working pressure is low, the direct-acting or step-by-step direct-acting principle must be used; when the minimum working pressure difference is above 0.04Mpa, direct-acting, step-by-step direct-acting, and pilot-operated types can be selected.
4. Electrical selection: AC220V and DC24 should be preferred for voltage specifications as much as possible.
5. Choose according to the length of continuous working time: normally closed, normally open, or continuous power on
1) When the solenoid valve needs to be opened for a long time, and the duration is longer than the closing time, the normally open type should be selected;
2) If the opening time is short or the opening and closing time is not long, choose the normally closed type;
3) However, for some working conditions used for safety protection, such as furnace and kiln flame monitoring, the normally open type cannot be selected, and the long-term energized type should be selected.
6. Select auxiliary functions according to environmental requirements: explosion-proof, non-return, manual, waterproof fog, water shower, diving.
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