Bellows Material---Stainless Steel

Bellows Material

      The main materials of bellows we used are stainless steel SS304,SS316L,SS316,SS321. They have different properties and prices which customer can choose them according to their need by themself. 

Stainless steel - Type 300 austenitic series 

304 (ASTM A240-304)

Services a wide range of applications.It resists organic chemicals,dye stuff,and a wide variety of inorganic chemicals.Type 304 resists nitric acid and sulfuric acids at moderate temperatures and concentrations.It is used extensively in piping systems conveying petroleum products,compressed air, steam,flue gas,and lique fied gases at cryogenic temperatures.The temperature range varies from -324 to 1200 degrees F. 

304L (ASTM A-240-304L)

Has a maximum carbon content of 0.03% versus 0.08% for type 304.This lower carbon content eliminates the problem of chromium carbide precipitation and makes it more resistant to intergranular corrosion.It is preferred over 304 for nitric acid service. 

316 (ASTM A-240-316)

This alloy contains more nickel than the 304 types.The addition of 2% to 3% molybdenum gives it improved corrosion resistance compared to 304 especially in chloride environments that tend to cause pitting.Some typical uses are flue gas ducts,crude oil systems high in fulfur,heat exchangers,and other critical applications in the chemical and petrochemical industries. 

316L (ASTM A-240-316L)

With its low carbon content of 0.03% maximum,it lends itself to highly corrosive applications where intergranular corrosion is a hazard. 

321(ASTM A240-321)

The addition of titanium to this stainless steel acts as a carbide stabilizing element that prevents carbide precipitation when the material is heated and cooled through the temperature range of 800 to 1650 degrees F. 321 finds uses in many of the same applications as Type 304,where the added safeguard from intergranular corrosion is desired.The standard catalog exhaust joints are made from this material because of the high operating temperatures they withstand. 

         Which stainless steel of bellows you used offen ?