ASTM A105 is the standard specification for carbon steel forgings for piping applications including flanges, fittings and valve parts, etc.
ASME B16.5 is a standard for Pipe Flanges and Flanged Fittings that covers flanges sizes from NPS ½” to 24”. In this standard, flanges are classified based on their pressure-temperature rating which is also known as a flange class.
A350 – This specification covers several grades of carbon and low alloy steel forged or ring-rolled flanges (LF2 in low-temp applications).
ASTM A105 is an ASTM specification dealing with forged carbon steel piping components.
Flanges are used to join two joints of pipe.
Pipe flanges are mostly used at places where ordinary pipes valves and other tools are required to be dismantled for maintenance purposes.