3. Selecting the solenoid valve according to the pressure parameter: principle and structure variety.
1) nominal pressure: this parameter is the same as that of other general valves, according to the nominal pressure of pipeline.
2) work pressure: if the work pressure is low, the principle of direct motion or step direct movement must be selected; the minimum working pressure difference is directly operated, the step direct movement and the pilot can be selected when the pressure difference is above 0.04Mpa.
4, electrical selection: voltage specifications should try to give priority to the selection of AC220V and DC24, which is more convenient.
5, according to the length of working hours to choose: normally closed, often open, or sustainable power.
1) when the solenoid valve needs to open for a long time, and the continuous time is longer than the closing time, the normally open type should be used.
2) if the opening time is short or the time of opening and closing is not enough, then the normally closed type is chosen.
3) however, some of the working conditions for safety protection, such as furnace and kiln flame monitoring, can not be selected normally.
6, select auxiliary functions according to environmental requirements: explosion protection, check, manual, waterproof fog, water spray, diving.