2.2.1 Letter codes for shaft seals
Pos. 14 in NBS type key example.
Code
example
Description
Code explanation
B
Shaft seal type
A: O-ring seal with fixed driver
B: Rubber bellows seal D: O-ring seal, balanced
H: Cartridge seal, balanced
Q
Material of rotating seal face
A: Carbon, metal-impregnated with antimony which is not approved for potable water
B: Carbon, resin-impregnated
Q: Silicon carbide
Q
Material of stationary seal
A: Carbon, metal-impregnated with antimony which is not approved for potable water
Q: Silicon carbide
E
Material of secondary seal and other
rubber and composite parts, except
the wear ring
E: EPDM
V: FKM (Viton®)
F: FXM (Fluoraz®)
K: FFKM (Kalrez®)
X: HNBR
U: Dynamic O-rings in FFKM and static O-rings in PTFE
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English (GB)