Pipe flanges standards
Pipe flanges
There are many different flange standards to be found worldwide. To
allow easy functionality and inter-changeability, these are designed to
have standardised dimensions. Common world standards include
ASA/ANSI/ASME (USA), PN/DIN (European), BS10 (British/Australian), and
JIS/KS (Japanese/Korean).
In most cases these are not interchangeable (e.g. an ANSI/ASME flange
will not mate against a JIS flange). Further, many of the flanges in
each standard are divided into "pressure classes", allowing flanges to
be capable of taking different pressure ratings. Again these are not
generally interchangeable (e.g. an ANSI/ASME 150 will not mate with an
ANSI/ASME 300).
These pressure classes also have differing pressure and temperature
ratings for different materials. Unique pressure classes for piping can
also be developed for a process plant or power generating station; these
may be specific to the corporation, engineering procurement and
construction (EPC) contractor, or the process plant owner. The ANSI/ASME
pressure classes for Flat-Face flanges are 125# and 250#. The classes
for Ring-Joint, Tongue & Groove, and Raised-Face flanges are 150#,
300#, (400# - unusual), 600#, 900#, 1500#, and 2500#.
The flange faces are also made to standardized dimensions and are
typically "flat face", "raised face", "tongue and groove", or "ring
joint" styles, although other obscure styles are po
