ASTM A350 (ASME SA350) is the standard specification for carbon steel and low alloy steel forged flanges and flanged fittings for low temperature services.

Common use grade is ASTM A350 LF2 Class 1, corresponding material for piping in ASTM A333 Grade 6 and pipe fittings in ASTM A420 WPL6. With yield strength minimum 240 Mpa, and tensile strength in 480 Mpa to 655 Mpa, impact test temperature at -45℃.

Our Supply Range

Grades: ASTM A350/ ASME SA350 Grade LF2, LF1, LF3, LF5, LF6, LF9, LF787, Class 1, 2, 3
Outer Diameters: 1/2'' to 24'' in ASME B16.5, up to 60'' in ASME B16.47
Wall Thickness Schedule: SCH 10, SCH 40, SCH 160 comply with ASME B16.9
Pressure Class: Class 150, 300, 600, 900, 1500, 2500
Manufacturing Standards: ASME B16.5, ASME B16.47 A, B

Standards Scope

ASTM A350 covers several grades of carbon and low-alloy steel forged or ring-rolled flanges, forged fittings and valves intended primarily for low-temperature service and requiring notch toughness testing. They are made to specified dimensions, or to dimensional standards, such as the ASME and API Specifications referenced in Section 2. Although this specification covers some piping components machined from rolled bar and seamless tubular materials, it does not cover raw material produced in these product forms.

Product furnished in ASTM A350/ ASME SA350 shall conform to the requirements of Specification A961/A961M, including any supplementary requirements that are indicated in the purchase order. Failure to comply with A961/A961M will be considered nonconformance with A350. And in case of conflict between ASTM A350 and A961/A961M, this specification shall prevail.

• Weld Neck Flange

• Blind Flange

• Slip On Flange

  STM A350 Flange DatasheetASTM A350 Flange Datasheet

  Chemical Composition
  
  Mechanical Properties
  Tension Tests Requirements—The material shall conform to requirements for tensile properties in below table.

Heat Analysis and Product Analysis
A chemical heat analysis and product analysis in accordance with Specification A961/A961M shall be made and conform to the requirements as to chemical composition prescribed in this table. Leaded steels shall not be permitted. Product analysis

Impact Test Temperature under ASTM A350 Flanges
Test Specimens by 10mm x 10mm

Impact test values: Charpy V-Notch Energy Requirements for specimens 10mm by 10mm.

Referenced Documents

ASTM Standards:

• A788/A788M Specification for Steel Forgings, General Requirements

• A961/A961M Specification for Common Requirements for Steel Flanges, Forged Fittings, Valves, and Parts for Piping Applications
  ASME Standards:

• B 16.5 Steel Pipe Flanges and Flanged Fittings

• B 16.9 Factory-Made Wrought Steel Butt-Welding Fittings

• B 16.10 Face-to-Face and End-to-End Dimensions of Ferrous Valves

• B 16.11 Forged Steel Fittings, Socket-Welding and Threaded

• B 16.30 Unfired Pressure Vessel Flange Dimensions

• B 16.34 Valves-Flanged, Threaded, and Welding End

• B 16.47 Large Diameter Steel Flanges

• ASME Boiler and Pressure Vessel Code
  AWS Standards:

• A 5.1 Mild Steel Covered Arc-Welding Electrodes

• A 5.5 Low-Alloy Steel Covered Arc-Welding Electrodes
  API Standards:

• 600 Steel Gate Valves with Flanged or Butt-Welding Ends

• 602 Compact Design Carbon Steel Gate Valves for Refinery Use

• 605 Large Diameter Carbon Steel Flanges

  Manufacture - Melting and Forging

  Melting Process - The steel shall be produced by any of the following primary processes: open-hearth, basic oxygen, electric-furnace, or vacuum-induction melting (VIM). The primary melting may incorporate separate degassing or refining, and may be followed by secondary melting using electroslag remelting (ESR), or vacuum-arc remelting (VAR).

Discard - A sufficient discard shall be made to secure freedom from injurious piping and undue segregation.

Forging Process
Material for forgings shall consist of ingots, or forged, rolled, or strand cast blooms, billets, slabs, or bars.

Heat Treatment

After hot working and before reheating for heat treatment, the forging shall be allowed to cool substantially below the transformation range.

Forgings grades except Grade LF787, should be heat treated in normalized, or normalized and tempered, or quenched and tempered. By manufacturer's option, material that performed in quenched and tempered could be normalized prior to the austenitize/quenched operation.

No limitation on size is intended beyond the ability of the manufacturer to obtain the specified requirements. However, Class 3 of Grade LF787 is only available in the quenched-and-precipitation heat treated condition.

Hydro-static Test

Forgings manufactured under ASTM A350/ ASME SA350 shall be performed with a hydro-static test compatible with the rating of the finished item. Such tests shall be conducted by the manufacturer only when Supplementary Requirement S57 of Specification A961/A961M is specified.

ASTM A105 is the standard specification for carbon steel forging flanges.

Standard Scope

ASTM A105 covers forged carbon steel flange and piping components for ambient and higher-temperature service in pressure systems. It also includes pipe fittings, valves and similar parts. The maximum weight manufactured forging part follows by this standard is 10000 bounds (4540kg). The larger forgings can according by the standard A 266/A266M. This specification do not covers tube sheets and hollow cylindrical forgings for pressure vessel shells .

This specification does not covers raw material which round bar and seamless tubular produced piping components.

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:

• B16.5 Dimensional standard for steel pipe flanges and flanges 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

• B16.47 Large diameter steel flanges

• 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

These components can be welded. Welding procedures must comply with ASME Boiler and Pressure Vessel Code Section IX.

Forging

ASTM A105 carbon steel can be forged at temperatures in the range of 2200 to 1700 F followed by quenching and tempering or normalizing.

Annealing

Forged parts can be cooled to below 1000 degrees Fahrenheit and then heated to between 1550 degrees Fahrenheit and 1,700 degrees Fahrenheit. Then carry out slow furnace cooling.

Hydro-static Test

Hydro-static Test shall be conducted by the forging manufacture only when Supplemental S57 of ASTM A961 is specified.

法兰的分类

1按化工行业标准分

整体法兰（IF）、螺纹法兰（Th）、板式平焊法兰（PL）、带径对焊法兰（WN）、带颈平焊法兰（SO）、承插焊法兰（SW）、对焊环松套法兰（PJ/SE）、平焊环松套法兰（PJ/RJ）、衬里法兰盖（BL（S））、法兰盖（BL）。

2按石化行业标准分

螺纹法兰（PT）、对焊法兰（WN）、平焊法兰（SO）、承插焊法兰（SW）、松套法兰（LJ）、法兰盖（不表注）。

3按机械行业标准分

整体法兰、对焊法兰、板式平焊法兰、对焊环板式松套法兰、平焊环板式松套法兰、翻边环板式松套法兰、法兰盖。

4按国家标准分

整体法兰、螺纹法兰、对焊法兰、带颈平焊法兰、带颈承插焊法兰、对焊环带颈松套法兰、板式平焊法兰、对焊环板式松套法兰、平焊环板式松套法兰、翻边环板式松套法兰、法兰盖。

体法兰：

常常是将法兰与设备、管子、管件、阀门等做成一体，这种型式在设备和阀门上常用。

密封面形式：

平面（FF）、突面（RF）、凸面（M）、凹面（F）、凹凸面（MF）、榫面（T）槽面（G）、榫槽面（TG）、环连接面（RJ）。

法兰材质有：

20#、A105、Q235A、12Cr1MoV、16MnR、15CrMo、18-8、321、304、304L、316、316L等。

法兰中英文对照表

法兰 Flange

整体管法兰 integral pipe flange

钢管法兰 steel pipe flange

螺纹法兰 threaded flange

滑套法兰（包括平焊法兰） slip-on flange （SO）; slip-on welding flange

承插焊法兰 socket welding flange

松套法兰 lap joint flange （LJF）

对焊法兰 welding neckflange （WNF）

法兰盖 blind flange, blind

孔板法兰 orifice flange

异径法兰 reducing flange

盘座式法兰 pad type flange

松套带颈法兰 loose hubbed flange

焊接板式法兰 welding plate flange

对焊环 welding neck collar （与stub end相似）

平焊环 welding-on collar

突缘短节 stub end, lap

翻边端 lapped pipe end

松套板式法兰 loose plate flange

压力级 pressure rating, pressure rating class

压力—温度等级 pressure-temperature rating

法兰密封面，法兰面 flange facing

突面 raised face （RF）

凸面 male face （MF）

凹面 female face （FMF）

榫面 tongue face

槽面 groove face

环连接面 ring joint face

全平面；满平面 flat face; full face （FF）

光滑突面 smooth raised face （SRF）

法兰面加工 facing finish

粗糙度 roughness

光滑的 smooth

齿形 serrated

均方根 root mean square （RMS）

算术平均粗糙高度 arithmetical average roughness height （AARH）

配对法兰 companion-flange

美标法兰的材质分类：

1、碳钢（Carbon Steel）：

ASTM A105,20#、Q235、16Mn、 Q345b、ASTM A350 LF1，LF2 CL1/CL2，LF3 CL1/CL2、ASTM A694 F42，F46，F48，F50，F52，F56，F60，F65，F70。

2、不锈钢（Stainess Steel）：

ASTM A182 F304、304L、 F316、316L、1Cr18Ni9Ti、0Cr18Ni9Ti、321、18-8。

3、合金钢（Alloy Steel）：

ASTM A182 F1、 F5a、 F9、 F11、 F12、 F22、 F91、A182F12、A182F11、16MnR、Cr5Mo、12Cr1MoV、15CrMo、12Cr2Mo1、A335P22、St45.8/Ⅲ。