Page 215 - b.safe catalog

FFKM – Perfluoro-Caoutchouc
An elastic sealing material with natural recovery and good accommodation
to the sealing surfaces and a chemical resistance comparable with PTFE. FFKM O-rings have a very high chemical and thermal resistance. Such seals can withstand virtually all kinds of chemicals and can be used at long dura- tion conditions with temperatures up to +260 °C. Perfluoro-caoutchouc is better known under the trade names KALREZ® by DuPont, CHEMRAZ® by Greene Tweed.
Elastomers - Chemical Resistance
... CF2
CF2 X
CF CF Y O
CF3
CF2 CF ...
Br
b.safeTECHNICAL INFORMATION 183
n
Classes of substances at 20°C
NBR
FKM
FFKM
EPDM
Water
++
++
++
++
Acids
+
+
++
++
Lyes
+
+
o
++
Oils and fats
+
++
++
-
Fuels
+
++
++
-
Ozone
o
++
++
++
Hydrocarbon, aliphatic
++
++
++
-
Hydrocarbon, aromatic
-
++
++
-
Hydrocarbon, chlorinated
-
++
++
-
Temperature range, °C
-40 to +130
-20 to +200
-20 to +250
-30 to +140
Definition: - not suitable, not recommended o possible, moderate to good
+ good
+++ very good, best choice