Corrosion of Linings
195
in contact with, especially organic liquids. This can result in swelling, cracking, and penetration to the substrate of an elastomeric-lined vessel. Swelling
can cause softening of the elastomer, and in a lined vessel, introduce high
stresses and failure of the bond. If an elastomeric lining has high absorption,
permeation will probably result. Some elastomers, such as the fluorocarbons,
are easily permeated but have very little absorption. An approximation of
the expected permeation and/or absorption of an elastomer can be based on
the absorption of water. These data are usually available.
TabLE 6.3
Elastomers Used as Liners
Elastomer
Temperature Range
(°F)
(°C)
Minimum
Maximum
Minimum
Maximum
Natural rubber, NR
−39
175
−50
80
Butyl rubber, IR
−30
300
−34
149
Chlorobutyl rubber, CIIR
−30
300
−34
149
Neoprene, CR
−13
203
−25
95
Hypalon, CSM
−20
250
−30
121
Urethane rubber, AU
−65
250
−54
121
EPDM rubber
−65
300
−54
149
Nitrile rubber, NBR, Buna-N
−40
250
−40
121
Polyester elastomer, PE
−40
302
−40
150
Perfluoroelastomers, FPM
−58
600
−50
316
Fluoroelastomers, FKM
−10
400
−18
204