ASTM A234 Carbon Steel Pipe Fittings
ASTM A234 is the standard specification for pipe fittings of wrought carbon steel and alloy steel for moderate and high-temperature service. The Cr-Mo low alloy steel pipe fittings has been separately listed on our website. Carbon steel pipe fittings manufactured to ASMT A234 are usually furnished in butt-welding form in accordance with ASME B16.9 or ASME B16.49. There are two carbon steel grades: WPB and WPC, of which ASTM A234 WPB is mostly often used in pipeline industry. The A234 WPB butt-welding pipe fittings include elbows, bends, returns, tees, reducers, end caps, crosses, lap joint stub ends, nipples and couplings.
1. Chemical Composition of ASTM A234 WPB & WPC
Element | Content, % | |
ASTM A234 WPB | ASTM A234 WPC | |
Carbon [C] | ≤0.30 | ≤0.35 |
Manganese [Mn] | 0.29-1.06 | 0.29-1.06 |
Phosphorus [P] | ≤0.050 | ≤0.050 |
Sulfur [S] | ≤0.058 | ≤0.058 |
Silicon [Si] | ≥0.10 | ≥0.10 |
Chromium [Cr] | ≤0.40 | ≤0.40 |
Molybdenum [Mo] | ≤0.15 | ≤0.15 |
Nickel [Ni] | ≤0.40 | ≤0.40 |
Copper [Cu] | ≤0.40 | ≤0.40 |
Vanadium [V] | ≤0.08 | ≤0.08 |
2. Mechanical Properties of ASTM A234 WPB & WPC
ASTM A234 Grades | Tensile Strength, min. | Yield Strength, min. | Elongation %, min | |||
ksi | MPa | ksi | MPa | Longitudinal | Transverse | |
WPB | 60 | 415 | 35 | 240 | 22 | 14 |
WPC | 70 | 485 | 40 | 275 | 22 | 14 |
*2. Unless required, hardness value doesn’t need to be reported.
3. Manufacture
The ASTM A234 carbon steel pipe fittings may be made from seamless pipes, welded pipes or plates by shaping operations of pressing, piercing, extruding, bending, fusion welding, machining, or by a combination of two or more these operations. All welds including welds in tubular products from which fittings are made shall be made in accordance with ASME Section IX. Post-weld heat treatment at 1100 to 1250°F[595 to 675°C] and radiographic examination shall be performed after the welding process.
4. Heat Treatment
Hot formed A234 WPB & WPC fittings upon which the final forming operation is completed at a temperature above 1150°F[620°C] and below 1800°F[980°C] need not be heat treated provided they are cooled in still air. Hot-formed A234 WPB and WPC fittings finished at temperature in excess of 1800°F[980°C] shall be subsequently annealed, normalized, or normalized and tempered.
A234 WPB & WPC pipe fittings over 12″[DN300] which are produced by locally heating a portion of the fitting stock to any temperature for forming, shall be subsequently annealed, normalized, or normalized and tempered. Fittings with a carbon content less than 0.26%, 12″ and smaller, shall not require heat treatment after forming a locally heated portion of the fitting. Cold-formed WPB and WPC fittings, upon which the final forming operation is completed at a temperature below 1150°F[620°C], shall be normalized, or shall be stress relieved at 1100 to 1275°F[595-690°C].
5. Tests and Examinations
ASTM A234 WPB or WPC fittings shall be furnished free of injurious imperfections such as dents, crackings, scratches, etc. Rigorous dimensional examination and visual inspection shall be performed. PMI heat analysis and tensile tests shall be performed to determine its chemical composition and mechanical properties. When required, other tests including Liquid Penetrant Inspection, Magnetic Particle Examination, Eddy-Current Test and Ultrasonic Test may be performed.