ASTM A105 Flange Specification

ASTM A105/A105M specifies forged carbon steel piping components, including flanges, fittings, valves and similar parts, for ambient- and higher-temperature service in pressure systems. The current active edition is ASTM A105/A105M-26. For flange procurement, ASTM A105/A105M primarily defines the material and forging requirements; flange NPS, pressure Class, facing, drilling pattern and dimensional configuration are established separately by the applicable dimensional standard, such as ASME B16.5 or ASME B16.47.

This distinction is important when specifying an ASTM A105 flange. A designation such as “ASTM A105” identifies the forged carbon steel material specification, but it does not by itself define a complete flange. The purchase specification also needs the flange type, dimensional standard, NPS, Class, facing and other connection details required by the piping system.

Standard Scope

ASTM A105/A105M covers forged carbon steel piping components manufactured either to purchaser-specified dimensions or to dimensional standards referenced by the specification, including applicable ASME, MSS and API standards.

Individual forgings under ASTM A105/A105M are limited to a maximum weight of 10,000 lb [4540 kg]. Larger forgings may be ordered to ASTM A266/A266M. Tubesheets and hollow cylindrical forgings for pressure-vessel shells are outside the scope of ASTM A105/A105M.

The specification may cover certain piping components machined from rolled bar or seamless tubular products; however, it does not cover the raw bar or seamless tubular material itself. Supplementary testing or inspection requirements apply when they are specifically invoked by the purchaser.

Referenced documents

The following list of standard apply to these specification:

ASTM standards:

• A266/A266M Specification for carbon steel forgings for pressure vessel components.
• A675/A675M Specification for hot-rolled, special quality and mechanical properties, carbon steel bars.
• A696 Specification for steel bars, carbon, hot-rolled or cold-finished,special quality, for pressure piping components.
• A788/A788M Specification for steel forgings, general requirements.
• A961/961M general requirements for steel flange, forging fittings, valve and parts for piping applications.

MSS standard:

• SP44 Standard for steel pipe line flanges

ASME Standard:

• ASME B16.5 — Pipe Flanges and Flanged Fittings
• B16.9 Wrought steel butt-welding fittings
• B16.10 Face-to-face and end-to-end dimensions of ferrous valves
• B16.11 Forged steel fittings, socket weld and threaded
• B16.34 Valves connect by flanges, threaded and welding end
• ASME B16.47 — Large Diameter Steel Flanges, NPS 26 Through NPS 60
• ASME boiler and pressure vessel code:

API standard:

• API-600 Flanged and butt-Welding-end steel gate valves
• API-602 Compact design carbon steel gate valves for refinery use

Chemical Composition

A The sum of copper, nickel, chromium, molybdenum and vanadium shall not exceed 1.00%.
B The sum of chromium and molybdenum shall not exceed 0.32%.

Mechanical Properties

Elongation

Terminology

For definitions of other terms used in this specification, find in specification A961/A961M.

Ordering information

See specification A961/A961M.

General requirements

If conflict between the requirements of this specification and Specification A961/A961M. Comply with this specification.

Heat treatment 

Heat treatment is not required except for flanges above Class 300, flanges of special design where the design pressure or design temperature are not known and for items over 4" NPS and above Class 300. When heat treatment is required, annealing, normalizing, Normalize and temper, normalize and quench and tempering shall be the applied methods.

Welding 

Repair welding, where permitted, is controlled by ASTM A105/A105M together with the applicable common requirements. For fabrication welding into a piping or pressure system, the governing construction code determines the welding requirements; ASME BPVC Section IX provides procedure and personnel qualification rules when invoked by that code.

Manufacturing and Heat Treatment

ASTM A105/A105M forgings are manufactured and heat treated as required to achieve the specified chemical composition, tensile properties, yield strength, elongation, reduction of area and hardness. Applicable heat-treatment routes include processes such as annealing, normalizing, tempering and quenching, subject to the requirements of the governing ASTM A105/A105M edition and ASTM A961/A961M.

Manufacturing temperature ranges used by an individual forging mill should not be presented as universal ASTM acceptance limits unless they are specifically required by the applicable specification, qualified manufacturing procedure or purchase order.

Repair welding, where permitted, is controlled by ASTM A105/A105M together with the applicable common requirements. For fabrication welding into a piping or pressure system, the governing construction code determines the welding requirements; ASME BPVC Section IX provides procedure and personnel qualification rules when invoked by that code.

How to Specify ASTM A105 Flanges for Procurement

ASTM A105/A105M defines the forged carbon steel material requirements, but a complete flange purchase specification requires additional dimensional and connection information. The following items should be confirmed in the RFQ or purchase order:

For weld neck flanges, the bore and welding-end configuration should match the connected pipe dimensions. For RTJ flanges, the facing type and groove dimensions need to be confirmed before production. Pressure Class should always be evaluated together with the applicable material group and operating temperature rather than treated as an independent pressure value.

FAQ

Q: What does ASTM A105 specify for a flange?

A: ASTM A105/A105M primarily specifies the forged carbon steel material and related manufacturing, chemical and mechanical requirements. It does not by itself define the complete flange dimensions, NPS, pressure Class or facing.

Q: Is ASTM A105 the same as ASME B16.5?

A: No. ASTM A105/A105M is a material specification for forged carbon steel piping components. ASME B16.5 defines pressure-temperature ratings, dimensions, tolerances, marking and other requirements for pipe flanges and flanged fittings within its applicable size and Class ranges.

Q: Is ASTM A105 intended for low-temperature flange service?

A: ASTM A105/A105M is intended for ambient- and higher-temperature pressure service. Where low-temperature service requires notch toughness testing, ASTM A350/A350M grades such as LF2 are commonly specified instead, subject to the project design requirements.

Q: What information is needed to order an ASTM A105 flange?

A: Specify ASTM A105/A105M together with the dimensional standard, flange type, NPS, Class, facing, bore or pipe schedule where applicable, quantity, and any supplementary inspection, testing or documentation requirements.

Related Products