Carbon steel flange depending on the sealing surface has a variety of
classification, the seal face different summarized below:
Flange sealing surface form and use of the environment has a direct
relationship, JiMeng flange factory also repeatedly referred to the
classification of the sealing surface in other documents.
1. Sealing face of the whole plane types (FF) : used in tablet form more
flange with smaller environment suitable for kg pressure, such as PN1.0
2. The concave and convex surface sealing surface type (FM) : more appeared
on the butt and socket welding flange, not commonly used in the system, in the
United States in European is more, more appeared in the PN4.0, PN6.4 MPA
pressure level, but not conducive to the gasket replacement.
3. The sealing face of the convex type (RF) : convex flange's most widely
used, more than in the U.S. the flange in PN2.0, PN5.0, PN10.0 MPA pressure
rating, in the European flange multi-purpose in PN1.6, PN2.5 MPA pressure
4. Grooved face seal face type (TG) : usage with concave and convex surface
is the same.
5. Ring groove surface sealing surface type (RJ) : often used with form of
butt welding, socket welding of no, multi-purpose in an environment of high
temperature and high pressure or both high, in the U.S. for PN10.0, PN15.0,
PN25.0, PN42.0 MPA pressure levels, also used in pressure in the European level
high pressure the ball above the flange.