ASTM A789 Standard pipe Specification.pdf
What is the ASTM A789 specification?
ASTM A789 is a standard specification for general-purpose seamless and weldable ferritic/austenitic (duplex) stainless steel tubes. These tubes are designed for applications requiring resistance to general corrosion and stress corrosion cracking, such as heat exchangers and general corrosive environments. However, these steels are prone to embrittlement at high temperatures, therefore prolonged use at temperatures above 600°F (315°C) is not recommended.
ASTM A789 Duplex Stainless Steel Tubing Specifications
| Type | Seamless Tubing |
|---|---|
| Specification | ASTM A789, ASME SA789 |
| Grades | UNS S31803, S32750, S32760 |
| Outside Diameter | 6 – 610 mm |
| Wall Thickness | 0.5 – 30 mm, Average Wall Or Minimum Wall |
| Length | Specific or Rando, standard 6000 mm length |
| Condition | Annealing Pickling, Beight Annealing |
| Form: | Round, Coiled Tubing |
| Application | Heat Exchanger, Boiler, Water, High Pressure, Ornamental Purpose |
| Manufacturing Method | Cold Rolling, Cold Drawn |
Duplex Stainless Steel Equivalents
| Steel Name | Steel Number | UNS | AISI |
|---|---|---|---|
| X2CrMnNiN21-5-1 | 1.4162 | S32101 | 2101 LDX |
| X2CrNiN23-4 | 1.4362 | S32304 | 2304 |
| X2CrNiMoN12-5-3 | 1.4462 | S31803/S32205 | 2205 |
| X2CrNiMoN25-7-4 | 1.4410 | S32750 | 2507 |
| X2CrNiMoCuEWN25-7-4 | 1.4501 | S32760 | Zeron 100 |
SA789 Duplex Steel Chemical Composition
| UNS Designation | C | Mn | P | S | Si | Ni | Cr | Mo | N | Cu | Others |
|---|---|---|---|---|---|---|---|---|---|---|---|
| S31803 | 0.030 | 2.00 | 0.030 | 0.020 | 1.00 | 4.5–6.5 | 21.0–23.0 | 2.5–3.5 | 0.08–0.20 | . . . | . . . |
| S32202 | 0.030 | 2.00 | 0.040 | 0.010 | 1.00 | 1.00–2.80 | 21.5–24.0 | 0.45 | 0.18–0.26 | . . . | . . . |
| S32205 | 0.030 | 2.00 | 0.030 | 0.020 | 1.00 | 4.5–6.5 | 22.0–23.0 | 3.0–3.5 | 0.14–0.20 | . . . | . . . |
| S32550 | 0.04 | 1.50 | 0.040 | 0.030 | 1.00 | 4.5–6.5 | 24.0–27.0 | 2.9–3.9 | 0.10–0.25 | 1.50–2.50 | . . . |
| S32750 | 0.030 | 1.20 | 0.035 | 0.020 | 0.80 | 6.0–8.0 | 24.0–26.0 | 3.0–5.0 | 0.24–0.32 | 0.50 | . . . |
Mechanical Properties of ASME SA789 Seamless Stainless Steel Tubing
| Grade | Tensile strength, min., ksi [MPa] | Yield strength, min., ksi [MPa] | Hardness, Max Brinell | Elongation in 2 in., or 50mm, min, % |
|---|---|---|---|---|
| S32205 | 95 [655] | 70 [485] | 290 | 25 |
| S31803 | 90 [620] | 65 [450] | 290 | 25 |
| S32550 | 110 [760] | 80 [550] | 297 | 15 |
| S32760 | 109 [750] | 80 [550] | 300 | 25 |
| S32750 | 116 [800] | 80 [550] | 310 | 15 |
ASTM A789 Stainless Steel Tubing Heat Treatment
| UNS Designation | Temperature °F [°C] | Quench |
|---|---|---|
| S31200 | 1920–2010 [1050–1100] | Rapid Cooling In Water |
| S31260 | 1870–2010 [1020–1100] | Rapid Cooling In Air Or Water |
| S31500 | 1800–1900 [980–1040] | Rapid Cooling In Air Or Water |
| S31803 | 1870–2010 [1020–1100] | Rapid Cooling In Air Or Water |
| S32003 | 1850–2050 [1010–1120] | Rapid Cooling In Air Or Water |
| S32205 | 1870–2010 [1020–1100] | Rapid Cooling In Air Or Water |
| S32304 | 1700–1920 [925–1050] | Rapid Cooling In Air Or Water |
| S32506 | 1870–2050 [1020–1120] | Rapid Cooling In Air Or Water |
| S32520 | 1975–2050 [1080–1120] | Rapid Cooling In Air Or Water |
| S32750 | 1880–2060 [1025–1125] | Rapid Cooling In Air Or Water |
SA 789 Duplex Boiler Tubes Permissible Variations in Dimensions
| O.D. (d) mm | PVavw % | PVod mm | PVL mm | PVmiw % |
|---|---|---|---|---|
| d＜12.7 | ±15 | ±0.13 | (3, 0) | (30, 0) |
| 12.7≤d＜38.1 | ±10 | ±0.13 | (3, 0) | (20, 0) |
| 38.1≤d＜88.9 | ±10 | ±0.25 | (5, 0) | (20, 0) |
| 88.9≤d＜139.7 | ±10 | ±0.38 | (5, 0) | (20, 0) |
| 139.7≤d＜203.2 | ±10 | ±0.76 | (5, 0) | (20, 0) |
ASTM A789 Stainless Steel Tubing Tolerances
| Outside Diameter, In. [Mm] |
OD Tolerance, In. [Mm] |
Average Wall In Wall Thickness,% |
Minimum Wall In Wall Thickness, %, Over |
Minimum Wall In Wall Thickness, %, Under |
Cut Length, In. [Mm], Over |
Cut Length, In. [Mm], Under |
Thin Walled Tubes |
|---|---|---|---|---|---|---|---|
| Up To 1⁄2 [12.7], Excl | ±0.005 [0.13] | ±15 | 30 | 0 | 1⁄8 [3] | 0 | … |
| 1⁄2 To 11⁄2 [12.7 To 38.1], Excl | ±0.005 [0.13] | ±10 | 20 | 0 | 1⁄8 [3] | 0 | Less Than 0.065 In. [1.6 Mm] Specified |
| 11⁄2 To 31⁄2 [38.1 To 88.9], Excl | ±0.010 [0.25] | ±10 | 20 | 0 | 3⁄16 [5] | 0 | Less Than 0.095 In. [2.4 Mm] Specified |
| 31⁄2 To 51⁄2 [88.9 To 139.7], Excl | ±0.015 [0.38] | ±10 | 20 | 0 | 3⁄16 [5] | 0 | Less Than 0.150 In. [3.8 Mm] Specified |
| 51⁄2 To 8 [139.7 To 203.2], Incl | ±0.030 [0.76] | ±10 | 20 | 0 | 3⁄16 [5] | 0 | Less Than 0.150 In. [3.8 Mm] Specified |
ASTM A789 Tube Price List
| Product | Price in USD |
|---|---|
| ASTM A789 Tubing Size: 1/2 inch, 0.035" | US $ 15.00 |
| ASTM A789 Tubing Size: 1 inch, 0.065" | US $ 25.00 |
ASTM A789 Tube Testing
Positive Material Identification – PMI Testing
Hardness Test
Intergranular Corrosion (IGC) Test
Micro and MacroTest
Mechanical Testing Such as Tensile of Area
Pitting Resistance Test
Flaring Test
Chemical Analysis – Spectro Analysis
Flattening Test
What is the difference between ASTM A790 and A789?
The main difference is that ASTM A789 covers seamless and welded ferritic/austenitic stainless steel tubing for general service, often smaller in size and used for pressure vessels like heat exchangers, while ASTM A790 covers seamless and welded ferritic/austenitic stainless steel pipe for larger sizes and more demanding applications with higher pressure and corrosion resistance requirements. ASTM A790 specifically requires the use of duplex stainless steels, whereas A789 can cover both austenitic and duplex stainless steels.
