1. Indoor equipment or outdoor use with protective methods;
2. Outdoor outdoor installations are corroded by wind, sand, rain and sun, etc.;
3. Have a flammable, explosive gas or dust environment;
4. The environment in humid and dry tropics;
5. The temperature of the pipeline medium is as high as 450°C or more;
6. The ambient temperature is lower than -20℃;
7. Easy to be flooded or immersed in water;
8. Possess a radioactive material (nuclear power plant and radioactive material experimental device) environment;
9. The environment on the ship or the dock (with salt spray, mold, and humidity);
10. Occasions with severe vibration; occasions prone to fire.
