1. Indoor installations or outdoor applications with protective methods;
2. Outdoor installation, wind, sand, rain, sun and other erosion;
3. With flammable, explosive gas or dust environment;
4. Humid zone, dry tropics environment;
5. Pipe medium temperature up to 450 ℃;
6. Ambient temperature below-20 ℃;
7. Prone to flooding or flooding;
8. With radioactive material (nuclear power plant and radioactive material test device) environment;
9. The ship or dock pier (salt fog, mold, damp) environment;
10. Occasions with severe vibration, prone to fire;
