ASTM A312 Stainless steel pipe commonly used in many indstries,Chemical and Petrochemical,Oil and Gas fior corrosion resistance, high-temperature performance.
Here we would like to introduce briefly about this standard,what materail grade is available under this standard ASTM A312.
ASTM A312 Originally approved in 1948 ,Current edition approved Nov. 1, 2022. Published December 2022.
So ASTM A312-22 is the latest verison as of now.
ASTM A312 is a specification for seamless, welded, and heavily cold worked austenitic stainless steel pipes.
It covers nominal pipe sizes (NPS) and schedules, including various grades of austenitic stainless steels suitable for high-temperature and general corrosive service.
Material Grades: ASTM A312 covers a wide range of stainless steel grades, including but not limited to:
- Austenitic grades: such as TP304/L, TP316/L, TP321/H, TP347/H, TP310S, and others.
- Duplex and super duplex grades: such as UNS S31803, UNS S32205, UNS S32750, and UNS S32760.
Grades TP304H, TP309H, TP309HCb, TP310H, TP310HCb, TP316H, TP321H, TP347H, and TP348H are modifications of Grades TP304, TP309Cb, TP309S, TP310Cb, TP310S, TP316, TP321, TP347, and TP348, and are intended for high-temperature service.
ASTM A312 Manufacturing Processes: ASTM A312 specifies seamless, welded, and heavily cold worked pipes. Seamless pipes are produced by hot extrusion or piercing, while welded pipes are manufactured by welding strips or plates of stainless steel.
ASTM A312 Seamless Pipe
Pipe should be made from stainless steel billet in hot rolling or cold drawn, no any welding process during manufacturing, seamless pipe has better pressure to withstand, annealing solution and pickling finishing condition, applied for high temperature and corrosion environment.
ASTM A312 Welded Pipe
No additional metal using automatic welding process for welded pipe, made from stainless steel strip or plate, both single welding and double welding for option, smail diameter and arge diameter are available, annealing pickling finish.
ASTM A312 Dimensions Scope: ASTM A312 provides specifications for nominal pipe sizes (NPS) ranging from 1/8 inch to 30 inches, with schedules ranging from SCH 5S to SCH XXS. The standard also covers various wall thicknesses and pipe lengths.
Heat Treatment
All pipe shall be furnished in the heat-treated condition in accordance with the required heat treating temperature and cooling requirements, pipes shall be individually quenched in water or rapidly cooled by other means (direct quenched).
The pipe shall be free of scale and contaminating exogenous iron particles. Pickling, blasting, or surface finishing is not mandatory when pipe is bright annealed.
ASTM A312 Stainless Steel Pipe Tolerances
Outside Diameter
| Outside Diameter, NPS | Tolerance, Inch |
|---|---|
| 1/8 To 1-1/2, Incl | Over 1/16 Under 1/32 |
| Over 1-1/2 To 4, Incl | Over 1/32 Under 1/32 |
| Over 4 To 8, Incl | Over 1/16 Under 1/32 |
| Over 8 To 18, Incl | Over 3/32 Under 1/32 |
| Over 18 To 26, Incl | Over 1/8 Under 1/32 |
| Over 26 To 34, Incl | Over 5/32 Under 1/32 |
| Over 34 To 48, Incl | Over 3/16 Under 1/32 |
Wall Thickness
| NPS | Wall Thickness Tolerance, % |
|---|---|
| 1/8 To 2-1/2 Incl., All T/D Ratios | Over 20.2 Under 12.5 |
| Over 3 To 18 Incl., T/D Up To 5% Incl. | Over 22.5 Under 12.5 |
| Over 3 To 18, Incl., T/D > 5% | Over 15.0 Under 12.5 |
| 20 And Large, Welded, All T/D Ratios | Over 17.5 Under 12.5 |
| 20 And Large, Seamless, T/D Up To 5% Incl. | Over 22.5 Under 12.5 |
| >20 And Large, Seamless, T/D > 5% | Over 15.0 Under 12.5 |
ASTM A312 Welded And Seamless Pipe Sizes And Chart
ASTM A312 stainless steel pipe sizes and dimensions should conform to ANSI B36.19, nominal pipe size (NPS) ranges from NPS 1/8 [10.29 mm] to NPS 30 [762 mm], Schedule number for wall thickness from Sch 5s to Sch 80s, value stated respective for specific size, average wall and minimum wall pipe are available upon request.
Note over NPS 12 sizes are actual sizes, not like below NPS 12 size values.
| Nominal Size | OD | Wall Thickness, SCHEDULE | |||||
|---|---|---|---|---|---|---|---|
| NPS | DN | Mm | 5S | 10S | 40S | STD | 80S |
| 1∕8 | 6 | 10.3 | – | 1.24 | 1.73 | 1.73 | 2.41 |
| 1∕4 | 8 | 13.7 | – | 1.65 | 2.24 | 2.24 | 3.02 |
| 3∕8 | 10 | 17.2 | – | 1.65 | 2.31 | 2.31 | 3.2 |
| 1∕2 | 15 | 21.3 | 1.65 | 2.11 | 2.77 | 2.77 | 3.73 |
| 3∕4 | 20 | 26.7 | 1.65 | 2.11 | 2.87 | 2.87 | 3.91 |
| 1 | 25 | 33.4 | 1.65 | 2.77 | 3.38 | 3.38 | 4.55 |
| 1 1∕4 | 32 | 42.2 | 1.65 | 2.77 | 3.56 | 3.56 | 4.85 |
| 1 1∕2 | 40 | 48.3 | 1.65 | 2.77 | 3.68 | 3.68 | 5.08 |
| 2 | 50 | 60.3 | 1.65 | 2.77 | 3.91 | 3.91 | 5.54 |
| 2 1∕2 | 65 | 73 | 2.11 | 3.05 | 5.16 | 5.16 | 7.01 |
| 3 | 80 | 88.9 | 2.11 | 3.05 | 5.49 | 5.49 | 7.62 |
| 3 1∕2 | 90 | 101.6 | 2.11 | 3.05 | 5.74 | 5.74 | 8.08 |
| 4 | 100 | 114.3 | 2.11 | 3.05 | 6.02 | 6.02 | 8.56 |
| 5 | 125 | 141.3 | 2.77 | 3.4 | 6.55 | 6.55 | 9.53 |
| 6 | 150 | 168.3 | 2.77 | 3.4 | 7.11 | 7.11 | 10.97 |
| 8 | 200 | 219.1 | 2.77 | 3.76 | 8.18 | 8.18 | 12.7 |
| 10 | 250 | 273.1 | 3.4 | 4.19 | 9.27 | 9.27 | 12.7 |
| 12 | 300 | 323.9 | 3.96 | 4.57 | 9.53 | 9.53 | 12.7 |
| 14 | 350 | 355.6 | 3.96 | 4.78 | – | 9.53 | – |
| 16 | 400 | 406.4 | 4.19 | 4.78 | – | 9.53 | – |
| 18 | 450 | 457.2 | 4.19 | 4.78 | – | 9.53 | – |
| 20 | 500 | 508 | 4.78 | 5.54 | – | 9.53 | – |
| 22 | 550 | 558.8 | 4.78 | 5.54 | – | 9.53 | – |
| 24 | 600 | 609.6 | 5.54 | 6.35 | – | 9.53 | – |
| 26 | 650 | 660.4 | – | – | – | 9.53 | – |
| 28 | 700 | 711.2 | – | – | – | 9.53 | – |
| 30 | 750 | 762 | 6.35 | 7.92 | – | 9.53 | – |
Beveled Stainless Steel Pipe
Beveled end A312 stainless steel industrial pipe is used to joint fitting or other connectors, there are different angles and tolerances for special applications, it is easy to welding, and save installing time, cost effective.
Testing And Inspection
- Mechanical Tests
- Grain Size Determinations
- Weld Decay Tests
- Transverse or Longitudinal Tension Test
- Hydrostatic or Nondestructive Electric Test
- Flattening Test (option)
- Radiographic Examination (option)
- Intergranular Corrosion Test (option)
- Weld Decay Test (option)
Reference Documents
- ASTM A999 / A999M – Standard Specification for General Requirements for Alloy and Stainless Steel Pipe
- ASTM A1016 / A1016M – Standard Specification for General Requirements for Ferritic Alloy Steel, Austenitic Alloy Steel, and Stainless Steel Tubes
- ASME B36.10 – Welded and Seamless Wrought Steel Pipe
- ASME B36.19 – Stainless Steel Pipe
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