ASTM A234
Basic Info
The ASTM A234 standard specifies the standard specifications for carbon steel and alloy steel fittings used for high-temperature services. The types of pipe fittings include elbows, bends, flanges, reducers, etc., used for pipeline connections. This standard covers the chemical composition, mechanical properties, and dimensional requirements of pipe fittings to ensure that products have good weldability and durability under high temperature and high pressure conditions
Characteristics
Wide Range of Applications: ASTM A234 fittings are designed for use in a variety of industries and applications, including oil and gas, petrochemical, power generation, and chemical processing plants.
High Temperature Resistance: These fittings are suitable for moderate and high-temperature services, making them ideal for applications where elevated temperatures are present.
Diverse Material Grades: ASTM A234 covers a range of material grades, including carbon steel, alloy steel, and stainless steel, allowing for flexibility in selecting the appropriate material for specific operating conditions.
ASTM A234 Data Sheet
Steel Grade
Dimensions and Tolerances
Equivalent Steel Grades
Mechanical Properties
Fabrication and Welding
ASTM A234 vs. ASTM A105:
Steel Grade
WPB
- Description: Represents carbon steel fittings for general industrial applications.
- Application: General industrial applications.
WPC
- Description: Represents carbon steel fittings for general industrial applications with lower service temperatures.
- Application: General industrial applications with lower service temperatures.
WP11
- Description: Represents 1% chromium – 1/2% molybdenum alloy steel fittings for high temperature and high pressure services.
- Application: High temperature and high pressure services.
WP22
- Description: Represents 2% chromium – 1% molybdenum alloy steel fittings for high temperature and high pressure services.
- Application: High temperature and high pressure services.
WP5
- Description: Represents 5% chromium – 1/2% molybdenum alloy steel fittings for high temperature and high pressure services.
- Application: High temperature and high pressure services.
WP9
- Description: Represents 9% chromium – 1% molybdenum alloy steel fittings for high temperature and high pressure services.
- Application: High temperature and high pressure services.
WP91
- Description: Represents 9% chromium – 1% molybdenum – 0.25% vanadium alloy steel fittings for high temperature and high pressure services.
- Application: High temperature and high pressure services.
WP304
- Description: Represents stainless steel 304 (austenitic stainless steel) fittings, typically used for corrosion resistance applications.
- Application: Corrosion resistance applications.
WP316
- Description: Represents stainless steel 316 (austenitic stainless steel) fittings, typically used for corrosion resistance applications.
- Application: Corrosion resistance applications.
Dimensions and Tolerances
Shape: Includes elbows, tees, reducers, caps, crosses, etc.
Size Range: From 1/2 inch to 48 inches (15mm to 1200mm).
Wall Thickness: Ranges from Schedule 5S to Schedule XXS.
Outside Diameter (OD): According to standard dimensions for each fitting.
Tolerances: As per ASTM A530/A530M or ASTM A1016/A1016M standards.
End Preparation: Beveled, plain, or according to other specific requirements.
Manufacturing Method: Can be seamless or welded.
Heat Treatment: Processes include normalizing, quenching, tempering, etc.
Equivalent Steel Grades
United States
- Equivalent Grades: UNS K03005, UNS K03006, UNS K03007
- Standard: ASTM A234/A234M
United Kingdom
- Equivalent Grades: BS 3602-1, BS 3603
- Standard: British Standard
Germany
- Equivalent Grades: DIN 2605-1, DIN 2609
- Standard: Deutsches Institut für Normung (DIN)
Japan
- Equivalent Grades: JIS G3454, JIS G3455, JIS G3456
- Standard: Japanese Industrial Standards (JIS)
Mechanical Properties
Tensile Strength
- Test Method: ASTM A370
- Requirement:
Grade WPB: ≥ 60,000 psi (415 MPa)
Grade WPC: ≥ 70,000 psi (485 MPa)
Yield Strength
- Test Method: ASTM A370
- Requirement:
Grade WPB: ≥ 35,000 psi (240 MPa)
Grade WPC: ≥ 40,000 psi (275 MPa)
Elongation
- Test Method: ASTM A370
- Requirement: For longitudinal strip tests:
Grade WPB: ≥ 22%
Grade WPC: ≥ 20%
Hardness
- Test Method: ASTM A370 or ASTM E18
- Requirement: Brinell Hardness (HB):
Grade WPB: ≤ 197 HB
Grade WPC: ≤ 229 HB
Impact Test
- Test Method: ASTM A370 or ASTM A370M
- Requirement:
- For Grade WPB:
Standard Impact Test Temperature: -20°F (-29°C)
Minimum Average Impact Energy: 20 ft-lb (27 J)
Minimum Single Impact Energy: 16 ft-lb (22 J)
2. For Grade WPC:
Standard Impact Test Temperature: -50°F (-45°C)
Minimum Average Impact Energy: 20 ft-lb (27 J)
Minimum Single Impact Energy: 16 ft-lb (22 J)
Fabrication and Welding
Fabrication Method
- Requirement: Fittings may be formed by forging, hammering, extruding, bending, fusion welding, machining, or other suitable means.
Heat Treatment
- Requirement: Fittings made from ASTM A234 shall be heat treated as necessary to achieve the desired properties. Heat treatment methods may include normalizing, annealing, quenching and tempering, or stress relieving.
Welding
- Requirement: Fittings may be welded using suitable welding processes, including buttwelding, socket welding, or threaded connections, as specified in applicable codes and standards.
Welding Procedure Specification (WPS)
- Requirement: Welding procedures shall be qualified in accordance with applicable codes and standards, such as ASME Section IX or AWS D1.1, to ensure the integrity of welded joints.
Post-Weld Heat Treatment (PWHT)
- Requirement: PWHT may be required for certain grades and thicknesses of fittings to relieve residual stresses and enhance material properties. The specific PWHT requirements shall be specified in the applicable material specification or welding procedure.
Inspection and Testing
- Requirement: Fittings shall be subject to visual inspection, dimensional inspection, and non-destructive testing (NDT) as required by applicable codes and standards. NDT methods may include radiographic testing (RT), ultrasonic testing (UT), magnetic particle testing (MT), or liquid penetrant testing (PT).
Documentation
- Requirement: Manufacturers shall provide documentation, including material test reports (MTRs), welder qualification records, welding procedure specifications (WPSs), and other relevant documentation, to verify compliance with specified requirements.
ASTM A234 vs. ASTM A105:
Material Type
- ASTM A234: Carbon and Alloy Steel
- ASTM A105: Carbon Steel
Application
- ASTM A234: Used for piping fittings, such as elbows, tees, reducers.
- ASTM A105: Used for forged carbon steel flanges, fittings, valves.
Mechanical Properties
- ASTM A234:
Tensile Strength: Varies depending on grade and heat treatment, typically ranging from 415 MPa to 690 MPa.
Yield Strength: Varies depending on grade and heat treatment, typically ranging from 240 MPa to 450 MPa.
Elongation: Varies depending on grade and heat treatment, typically ranging from 20% to 30%.
- ASTM A105:
Tensile Strength: 485 MPa minimum.
Yield Strength: 250 MPa minimum.
Elongation: 22% minimum.
Manufacturing Standards
- ASTM A234: Manufactured according to ASTM A234/A234M standard, which specifies the requirements for carbon and alloy steel pipe fittings. Dimensional specifications include ASME B16.9 for butt weld fittings and ASME B16.11 for socket weld and threaded fittings.
- ASTM A105: Manufactured according to ASTM A105/A105M standard, which covers carbon steel forgings for piping applications. Dimensional specifications include ASME B16.5 for flanges and ASME B16.11 for fittings.
Corrosion Resistance
- ASTM A234: Depending on alloy composition, ASTM A234 materials may exhibit good corrosion resistance in various environments, but additional surface treatments or coatings may be required for enhanced protection.
- ASTM A105: ASTM A105 materials are susceptible to corrosion, especially in acidic and corrosive environments, and may require additional protection measures such as galvanizing or coating.
Suitability
- ASTM A234: ASTM A234 fittings are suitable for use in high-pressure and high-temperature piping systems across various industries, including oil and gas, petrochemical, power generation, and chemical processing.
- ASTM A105: ASTM A105 flanges and fittings are commonly used in low to moderate pressure and temperature applications, such as petroleum refining, chemical processing, and power generation.
