ASME CODES
ASME/ANSI B16.5 – (Year) - Pipe Flanges and Flanged Fittings
The ASME B16.5 - 1996 Pipe Flanges and Flange Fittings standard covers pressuretemperature ratings, materials, dimensions, tolerances, marking, testing, and methods of
designating openings for pipe flanges and flanged fittings.
The standard includes flanges with rating class designations 150, 300, 400, 600, 900, 1500, and
2500 in sizes NPS 1/2 through NPS 24, with requirements given in both metric and U.S units.
The Standard is limited to flanges and flanged fittings made from cast or forged materials, and
blind flanges and certain reducing flanges made from cast, forged, or plate materials. Also
included in this Standard are requirements and recommendations regarding flange bolting,
flange gaskets, and flange joints.
ASME/ANSI B16.11 – (Year) - Forged Steel Fittings, Socket-Welding and Threaded
This Standard covers ratings, dimensions, tolerances, marking and material requirements for
forged fittings, both socket-welding and threaded.
ASME/ANSI B16.28 – (Year) - Wrought Steel Buttwelding Short Radius Elbows
and Returns
This Standard covers ratings, overall dimensions, testing, tolerances, and markings for wrought
carbon and alloy steel buttwelding short radius elbows and returns. The term wrought denotes
fittings made of pipe, tubing, plate, or forgings.
ASME/ANSI B16.36 – (Year) - Orifice Flanges
This Standard covers flanges (similar to those covered in ASME B16.5) that have orifice
pressure differential connections. Coverage is limited to the following:


(a) welding neck flanges Classes 300, 400, 600, 900, 1500, and 2500
(b) slip-on and threaded Class 300
ASME/ANSI B16.47 – (Year) - Large Diameter Steel Flanges: NPS 26 through NPS
60
This Standard covers pressure-temperature ratings, materials, dimensions, tolerances, marking,
and testing for pipe flanges in sizes NPS 26 through NPS 60 and in ratings Classes 75,
150,0300, 400, 600, and 900. Flanges may be cast, forged, or plate (for blind flanges only)
materials. Requirements and recommendations regarding bolting and gaskets are also included.
ASTM A-XXXX vs ASTM SA-XXXX
ASTM – American Society for Testing and Materials
ASME – American Society of Mechanical Engineers
BPVC – Boiler and Pressure Vessel Code
Some ASME codes specify materials such as ASTM A 105, whereas the material is listed as ASTM SA105 in other codes. The ASTM SA-105 specification says it is identical to ASTM A 105.
Is there any reason why the material is referred to as A105 and SA-105 if it is identical? Are most (or
all) SA-XXX's identical to A-XXX's? Are there any differences?
The A designator is for ASTM materials, the SA for ASME materials.
When the ASME Boiler and Pressure Vessel Code was formed, a materials subcommittee was
established to review other materials standards/specifications like ASTM and either adopt them in whole
or in part, with exceptions or editorial revisions.
To assure identity, the ASME Code committee elected to use a prefix S to denote that the material
specification was reviewed and approved for ASME Boiler and Pressure Vessel use. In some cases,
material can meet both ASTM and ASME specifications. In other cases, ASTM materials are not
acceptable for use in boiler or pressure vessel applications.
If you look at ASME II-A, Appendix A (at the front of the code), you'll find a listing of how the SA-xx
materials differ from the A-xx materials. In the case of SA-53 SA-105, they are identical to A-53 and A105.
In the case of SA-106, it is identical to A-106 "except for editorial differences in 8.1, 13.4, and 24.1 and
deletion of ASTM caveat 1.5."
Because of the review process, ASME is usually at least six months behind in getting ASTM materials
updated and approved to the latest edition by the ASME B&PV code committee..
JoeTank (Structural)
26 Feb 04 9:56
I believe you are misreading the ASME Code. The Code specifies ASME SAxxx material, not ASTM SAxxx
material.
The reason ASME Code specifies ASME material designations (rather than ASTM material designations)
is that each and every material must be accepted by the ASME Code Committee for Code construction.
Even though most of the ASTM and ASME material specs are identical, there are many ASTM materials
that are not acceptable for Code construction.
Steve Braune
Tank Industry Consultants
www.tankindustry.com
The difference between Class 1 and Class 2 in accordance with ASME SA 350
for LF2 is Charpy impact requirements
for LF2 Cl.1 - the minimum Charpy impact is 15 ft-lbs
@-50 deg F
for LF2 Cl.2 - the minimum Charpy impact is 20 ft-lbs
@0 deg F
If anyone is trying to register vessel design in Canada, using SA-350-LF2. You must state the class of
this material on your BOM's and drawings. Your design may be rejected due to failing to fully describe
the material being used.