ASTM A270 Sanitary pipe Standard Specification.pdf
What is ASTM A270 material?
ASTM A270 is a standard specification for sanitary (high hygiene requirements) pipes made of austenitic and ferritic stainless steel, suitable for industries with extremely high hygiene requirements, such as food, beverage, and biopharmaceutical processing. Commonly used grades include 304 and 316 stainless steel. This standard requires pipes to have extremely high surface finishes, specifies strict dimensional tolerances, and mandates mechanical property and non-destructive testing to ensure their suitability for sanitary applications.
What is the A270 material specification?
This specification covers seamless, welded, and heavily cold-worked welded austenitic and ferritic/austenitic stainless steel sanitary tubing for use in the dairy and food industries. These tubings have special surface treatments and cover tubing with a maximum outer diameter of 12 inches (300 mm).
What is the chemical composition of ASTM A270?
ASTM A270 specifies the chemical composition of various grades of austenitic stainless steel, most commonly 304L and 316L. For example, 304L has a maximum carbon content of 0.035% and a nickel content between 8% and 13%; while 316L has 2% to 3% molybdenum added to improve its corrosion resistance.
| Grade | UNS
Design |
Composition, % | ||||||||||
| C | Mn | P | S | Si | Cr | Ni | Mb | Ti | Nb | N | ||
| TP304 | S30400 | 0.08 | 2 | 0.045 | 0.03 | 1 | 18.0–20 | 8.0–11 | . . . | . . . | . . . | . . . |
| TP304L | S30403 | 0.035 | 2 | 0.045 | 0.03 | 1 | 18.0–20 | 8.0–13 | . . . | . . . | . . . | . . . |
| TP316 | S31600 | 0.08 | 2 | 0.045 | 0.03 | 1 | 16.0–18 | 10.0–14 | 2.00–3 | . . . | . . . | . . . |
| TP316L | S31603 | 0.035 | 2 | 0.045 | 0.03 | 1 | 16.0–18 | 10.0–14 | 2.00–3 | . . . | . . . | . . . |
| TP321 | S32100 | 0.08 | 2 | 0.045 | 0.03 | 1 | 17.0–19 | 9.0–12 | . . . | Ti 5 × (C+N) min, 0.70 max | . . . | 0.1 |
A270/A270M tubing Standard Mechanical Properties
ASTM A270 (also known as A270/A270M-15/19) specifies minimum tensile strength, minimum yield strength, minimum elongation, and maximum Rockwell hardness.
| Grade (UNS) | Tensile Strength, min (ksi [MPa]) | Yield Strength, min (0.2% offset) (ksi [MPa]) | Elongation in 2 in., min (%) | Rockwell Hardness, max |
|---|---|---|---|---|
| TP304 (S30400) | 75 [515] | 30 [205] | 35 | B90 |
| TP304L (S30403) | 70 [485] | 25 [170] | 35 | B90 |
| TP316 (S31600) | 75 [515] | 30 [205] | 35 | B90 |
| TP316L (S31603) | 70 [485] | 25 [170] | 35 | B90 |
| S31803 | 90 [620] | 65 [450] | 25 | C30.5 |
| 2205 (S32205) | 95 [655] | 70 [485] | 25 | C30.5 |
| 2507 (S32750) | 116 [800] | 80 [550] | 15 | C32 |
What is the tolerance of ASTM A270?
ASTM A270 stipulates that the wall thickness at any point cannot exceed 12.5% of the required wall thickness.
| OD Size | Nominal wall | Outside Dia | Length | Wall |
| 1/2″ (12.7) | 0.065″ (1.65) | +/-0.005 (0.13) | +1/8″ (3.18)/-0 | +/-10% |
| 3/4″ (19.1) | 0.065″ (1.65) | +/-0.005 (0.13) | +1/8″ (3.18)/-0 | +/-10% |
| 1″ (25.4) | 0.065″ (1.65) | +/-0.005 (0.13) | +1/8″ (3.18)/-0 | +/-10% |
| 1-1/2″ (38.1) | 0.065″ (1.65) | +/-0.008 (0.20) | +1/8″ (3.18)/-0 | +/-10% |
| 2″ (50.8) | 0.065″ (1.65) | +/-0.008 (0.20) | +1/8″ (3.18)/-0 | +/-10% |
| 2-1/2″ (63.5) | 0.065″ (1.65) | +/-0.010 (0.25) | +1/8″ (3.18)/-0 | +/-10% |
| 3″ (76.2) | 0.065″ (1.65) | +/-0.010 (0.25) | +1/8″ (3.18)/-0 | +/-10% |
| 4″ (101.6) | 0.083″ (2.11) | +/-0.015 (0.38) | +1/8″ (3.18)/-0 | +/-10% |
| 6″ (152.4) | 0.109″ (2.77) | +/-0.030 (0.76) | +3/16″ (4.76)/-0 | +/-10% |
| 8″ (203.2) | 0.109″ (2.77) | +/-0.030 (0.76) | +3/16″ (4.76)/-0 | +/-10% |
ASTM A270 Pressure Rating
ASTM A270 does not have a single "pressure rating"; instead, the pressure rating is determined by the tube's specific dimensions, such as outer diameter (OD) and wall thickness, as well as the material grade (e.g., 304, 316L). For example, a 1" OD, 0.065" wall ASTM A270 tube could have a working pressure of around 2,440 PSI, while a 1½" OD tube with the same wall thickness would have a lower pressure rating of approximately 1,630 PSI.
What size is ASTM A270 pipe?
ASTM A270 sanitary stainless pipe usually refers to the small pipe diameters, normally from 1/2" to 2 1/2", thickness from 0.049 in (1.24mm) to 0.15 in (3.81mm). The maximum outer diameter of ASTM A270 tubing is 12 inches (304.8 mm).
What is the difference between ASTM A269 and A270?
The main difference is that A270 tubing is commonly used in industries such as food and pharmaceuticals, and includes requirements such as removal of internal weld seams, internal wall polishing, and more stringent surface finish inspections. ASTM A269 tubing, on the other hand, is suitable for more general industrial applications, such as heat exchangers and condensers, where minor surface defects are permissible.
