Carbon steel Flange material introduction
ASTM A105/ A105 M-98, This specification covers standards for forged carbon steel piping components, that is, flanges, fittings, valves, and similar parts, for use in pressure systems at ambient and higher-temperature service conditions. Materials shall be subjected to heat treatment (annealing, normalizing, tempering, or quenching). Material shall conform to carbon, manganese, phosphorus, sulfur, silicon, copper, nickel, chromium, molybdenum and vanadium contents. The forgings shall be subjected to tension, hardness and hydrostatic tests, with the latter applicable when required. Material shall adhere to tensile strength, yield strength, elongation, reduction of area, and hardness requirements. Guidelines for retreatment, repair by welding, and product marking are given.
ASTM A181 M-95 b Class 60, ASTM A181 M-95 b Class 70, his specification covers nonstandard as-forged fittings, valve components, and parts for general service. Forgings made to this specification are limited to a maximum weight of 10 000 lb [4540 kg]. Larger forgings may be ordered to Specification A266/A266M.
ASTM A694/ A694M (F42, F46, F48, F50, F52, F56, F60, F65, F70), This specification covers carbon and alloy steel forgings for pipe flanges, fittings, valves, and parts for high-pressure transmission service. A chemical heat analysis of the steel shall be made, and the steel shall conform to specified chemical composition requirements. Materials adhere to testing and tensile property requirements as well.
ASTM A515/ A515M (Gr.55, 60, 65, 70), This specification covers carbon-silicon steel plates primarily for intermediate- and higher-temperature service in welded boilers and other pressure vessels. Plates are available in three grades having different strength levels: Grade 60; Grade 65; and Grade 70. The steel shall be killed and made to a coarse austenitic grain size practice. The steel shall conform to the chemical requirements specified. Tension test shall be made to conform to the requirements specified.
Standard
ASME B16.5, ASME B16.47 (Serie A and Serie B), API 6A ASME B16.36, ASME B16.48 and MSS SP44 are the key specifications covering the dimensions and the manufacturing tolerances of Flanges. ASME B16.25 covers the preparation of butt weld connections between pipes and Weld Neck Flange. MSS SP25 covers the marking system.
Today API Spec 6A and MSS SP-44 specify all flanges commonly used in surface drilling and production. These flanges have a long history and many flanges used in the past have been discontinued, or obsoleted and replaced by more modern configurations. Originally, all flanges related to pipe and became standard as weld neck, threaded and blind configurations. As equipment with integral flanges came to the oilfield, standardization became necessary for functional interchangeability.