First, select principle and structure of the solenoid valve according to the pressure parameters

1. Nominal pressure: this parameter is the same as that of other general valves and is determined according to the nominal pressure of the pipe.

2. Working pressure: if the working pressure is low, the principle of direct action or step by step direct action must be selected. When the minimum working pressure difference is above 0.04Mpa, direct action, step by step direct action and pilot type can be selected.

Secondly, select normally closed, normally open, or continuously electrification according to the duration of continuous operation

1. When the solenoid valve needs to be opened for a long time, and the duration of the continuous time surplus closing should be of the normally open type.

2. If the opening time is short or the opening and closing time is not long, the usual closed type is selected.

3. However, some working conditions used for safety protection, such as furnace and kiln flame monitoring, can not be opened normally and should be electrified for a long time.

Thirdly, select auxiliary functions such as explosion-proof, stop, manual, waterproof fog, water shower and diving according to the environmental requirements

1. Explosive environment: the corresponding explosion-proof level electromagnetic valve must be selected.

2. When the fluid in the tube has backflow phenomenon, OK71-N, OK72-N series with check function solenoid valve can be selected.

4. When manual operation of solenoid valve is needed, OK71-S, OK72-S series solenoid valve with manual function can be selected.

4. The water fountain must adopt the diving type electromagnetic valve (the protection level is above IP68).

5. Waterproof and dustproof varieties should be selected for open-air installation or dust multi-occasion (protection grade is above IP54).