ASTM A420 is the standard specification for pipe fittings of wrought carbon steel and alloy steel for low temperature service. These fitting, either of seamless or welded construction, are primarily used in pressure piping and pressure vessel service at low temperatures. Metals-Piping can provide all the four steel grades covered by ASTM A420: WPL6, WPL9, WPL3, and WPL8.
How to manufacture?
The raw material for these fittings shall be fully killed steel, consisting of forgings, bars, plates, sheet, and seamless or fusion welded tubular products(pipes, tubes, or cylinders). The steels shall be made using recognized melting practices necessary to produce steels that shall meet the impact requirements of ASTM A420.
The ASTM A420 fittings may be made by forging or forming operations including hammering, pressing, piercing, extruding, upsetting, working, bending, fusion-welding, or machining, or by a combination of two or more of these operations. The forming procedure shall be so applied that it will not produce injurious defects in the fittings. All the fittings shall be furnished free of welding repair. The welded joints of the fittings shall be finished in accordance with the requirements of Paragraph UW-35 (a) of Section VIII, Division 1 of ASME Boiler and Pressure Vessel Code.
Product & Standards
|
Standards |
Product |
|
ASME B16.9 |
Factory-Made Wrought Steel Butt Welding Threaded |
|
ASME B16.11 |
Forged Steel Fittings, Socked Welding Threaded |
|
ASME Section VIII Division 1 |
Pressure Vessels |
|
MSS SP-25 |
Standard Marking System for Valves, Fittings, Flanges, and Unions |
|
MSS SP-79 |
Socket Welding Reducer Inserts |
|
MSS SP-83 |
Steel Pipe Unions, Socket-Welding and Threaded |
|
MSS SP-95 |
Swage(d) Nipples and Bull Plugs |
|
MSS SP-97 |
Integrally Reinforced Forged Branch Outlet Fittings-Socket Welding, Threaded and Buttwelding Ends |
ASTM A420 Buttweld Fittings Chemical Composition
|
CHEMICAL COMPOSITION OF ASTM A420 |
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|
Elements |
WPL6, % |
WPL9, % |
WPL3, % |
WPL8, % |
|
Carbon [C] |
≤0.30 |
≤0.20 |
≤0.20 |
≤0.13 |
|
Manganese [Mn] |
0.50-1.35 |
0.40-1.06 |
0.31-0.64 |
≤0.90 |
|
Phosphorus [P] |
≤0.035 |
≤0.030 |
≤0.05 |
≤0.030 |
|
Sulfur [S] |
≤0.040 |
≤0.030 |
≤0.05 |
≤0.030 |
|
Silicon [Si] |
0.15-0.40 |
… |
0.13-0.37 |
0.13-0.37 |
|
Nickel [Ni] |
≤0.40 |
1.60-2.24 |
3.2-3.8 |
8.4-9.6 |
|
Chromium [Cr] |
≤0.30 |
… |
… |
… |
|
Molybdenum [Mo] |
≤0.12 |
… |
… |
… |
|
Copper [Cu] |
≤0.40 |
0.75-1.25 |
… |
… |
|
Columbium [Cb] |
≤0.02 |
… |
… |
… |
|
Vanadium[V] |
≤0.08 |
… |
… |
… |
*For grade WPL6, the limit for Columbium may be increased up to 0.05% on heat analysis and 0.06% on product analysis.
*Fittings of WPL3 made from plate or forgings may have 0.90 % max manganese.
*Fittings of WPL8 made from plate may have 0.98 % max manganese.
ASTM A420 Buttweld Fittings Mechanical Properties
|
ASTM A420/ A420M |
TENSILE STRENGTH, MIN. |
YIELD STRENGTH, MIN. |
ELONGATION %, MIN |
|||
|
Grade |
ksi |
MPa |
ksi |
MPa |
Longitudinal |
Transverse |
|
WPL6 |
65-95 |
415-655 |
35 |
240 |
22 |
12 |
|
WPL9 |
63-88 |
435-610 |
46 |
315 |
20 |
… |
|
WPL3 |
65-90 |
450-620 |
35 |
240 |
22 |
14 |
|
WPL8 |
100-125 |
690-865 |
75 |
515 |
16 |
… |
*All the elongation values are on the basis of standard round specimen, or small proportional specimen, min % in 4 D.
Post time: Oct-08-2021