Valve Coatings - Atmospheric Corrosivity Categories and Typical Environmental Examples
Item	Corrosivity Category	Exterior	Interior
1.1	C1 Very Low Corrsivity	-	Heated buildings with clean atmospheres, e.g. offices, shops, schools, hotels
1.2	C2 Low Corrosivity	Atmospheres with low level of pollution: mostly rural areas	Unheated buildings where condensation can occur, e.g. depots, sports halls
1.3	C3 Medium Corrosivity	Urban and industrial atmospheres, moderate sulfur dioxide pollution; coastal areas with low salinity	Production rooms with high humidity and some air pollution, e.g. food-processing plants, laundries, breweries, dairies
1.4	C4 High Corrosivity	Industrial areas and coastal areas with moderate salinity	Chemical plants, swimming pools, coastal ships and boatyards
1.5	C5 Very High Corrosivity	Industrial areas with high humidity and aggressive atmosphere and coastal areas with high salinity	Buildings or areas with almost permanent condensation and with high pollution
1.6	CX Extreme Corrosivity	Offshore areas with high salinity and industrial areas with extreme humidity and aggressive atmosphere and subtropical and tropical atmospheres	Industrial areas with extreme humidity and aggressive atmosphere
Valve Coatings - Water and Soil Categories
Item	Corrosivity Category & Environment	Environment and Structure Examples
2.1	IM1 Fresh Water	River installations, hydro-electronic power plants
2.2	IM2 SeaWater / Brackish Water	Immersed structures without cathodic protection, e.g. harbour areas with structures like sluice gates, locks or jetties
2.3	IM3 Soil	Buried tanks, steel piles, steel pipes
2.4	IM4 SeaWater / Brackish Water with Cathodic Protection	Immersed structures with cathodic protection，e.g. offshore structures