Stainless Steel Dairy Tube
-
International Standard
- Material Grades
- Outer Diameter
- Wall Thickness
- Surface
- Tube Type
- Mill Test Certificate(MTC)
- Certificate
- ASME BPE, ASTM A270, 3-A Standards, EN10357, DIN11850, AS1528.1, ISO2037
- AISI 304/304L/316/316L
- 1/4″ - 12"
- 0.035″ - 0.12″
- Grit 180, 240, 320
- Welded , Seamless
- EN10204 3.1
- ISO 9001:2015 , PED 2014/68/EU , AD 2000-WO
- 6.35mm - 304.8mm
- 0.89mm - 3.05mm
- ≤20Ra (0.5 μm) ID ≤30Ra (0.8 μm) OD
Stainless Steel Dairy Tube
- International Standard
- Material Grades
- Outer Diameter
- Wall Thickness
- Surface
- Tube Type
- Certificate
- ASTM A270 / ASME SA270 , 3-A Sanitary Standard
- AISI TP304/304L/316/316L
- 1/4″ - 12" 6.35mm - 304.8mm
- 0.035″ - 0.12″ 0.89mm - 3.05mm
-
Grit 180, 240, 320
≤20Ra (0.5 μm) ID ≤30Ra (0.8 μm) OD - Welded , Seamless
- ISO 9001:2015 , PED 2014/68/EU , AD 2000-WO
The stainless steel dairy tube is the essential artery of modern milk processing plants. Engineered for durability, hygiene, and efficiency, it forms the critical network for transporting raw milk, cream, whey, and finished products like yogurt or cheese.
Its primary virtue is its material: food-grade austenitic stainless steel (typically AISI 304 or 316). This is highly corrosion-resistant, non-reactive, and inert, ensuring no metallic taint or flavor transfer to the sensitive dairy fluids. The smooth, polished inner surface, or “finish,” is crucial. A high-grade mechanical or electropolished finish minimizes bacterial adhesion, prevents milkstone buildup, and allows for efficient Cleaning-in-Place (CIP) systems. Hot detergent and sterilizing solutions are pumped through the precisely welded, crevice-free tube circuits to meet stringent sanitary standards.
Beyond hygiene, the tubing is designed for durability under thermal and mechanical stress, handling both hot cleaning cycles and chilled products. Fittings are sanitary, with quick-release clamps for easy disassembly when needed. From the farm bulk tanker’s discharge line to the intricate piping between pasteurizers, separators, and filling machines, stainless steel dairy tube ensures that milk travels from cow to carton with uncompromised purity, safety, and quality. It is the unseen, yet indispensable, backbone of the dairy industry.
Dimension of ASTM A270 Dairy Tube
ASTM A270 is a standard specification for seamless and welded austenitic and ferritic/austenitic stainless steel food grade tubing. This standard covers stainless steel tubing used primarily in the dairy, food, pharmaceutical, and other high-purity industries where cleanliness and corrosion resistance are critical.
| DN | Tube OD | Wall Thickness | OD Tolerance | WT Tolerance | Length Tolerance | Weight |
|---|---|---|---|---|---|---|
| inch(mm) | inch(mm) | inch(mm) | inch(mm) | (kg/m) | ||
| 8 | 1/4" (6.35) | 0.035" (0.89) | +/-0.005" (0.13) | +/-10.0% | +1/8" (3.18) -0 | 0.124 |
| 15 | 1/2" (12.7) | 0.065" (1.65) / 0.049"(1.25) | +/-0.005" (0.13) | +/-10.0% | +1/8" (3.18) -0 | 0.454 |
| 20 | 3/4" (19.1) | 0.065" (1.65) / 0.049"(1.25) | +/-0.005" (0.13) | +/-10.0% | +1/8" (3.18) -0 | 0.717 |
| 25 | 1" (25.4) | 0.065" (1.65) / 0.049"(1.25) | +/-0.005" (0.13) | +/-10.0% | +1/8" (3.18) -0 | 0.976 |
| 40 | 1-1/2" (38.1) | 0.065" (1.65) / 0.049"(1.25) | +/-0.008" (0.20) | +/-10.0% | +1/8" (3.18) -0 | 1.50 |
| 50 | 2" (50.8) | 0.065" (1.65) / 0.049"(1.25) | +/-0.008" (0.20) | +/-10.0% | +1/8" (3.18) -0 | 2.02 |
| 65 | 2-1/2" (63.5) | 0.065" (1.65) | +/-0.010" (0.25) | +/-10.0% | +1/8" (3.18) -0 | 2.54 |
| 80 | 3" (76.2) | 0.065" (1.65) | +/-0.010" (0.25) | +/-10.0% | +1/8" (3.18) -0 | 3.06 |
| 100 | 4" (101.6) | 0.083" (2.11) | +/-0.015" (0.38) | +/-10.0% | +1/8" (3.18) -0 | 5.23 |
| 150 | 6" (152.4) | 0.109" (2.77) | +/-0.030" (0.76) | +/-10.0% | +1/8" (3.18) -0 | 10.32 |
| 200 | 8" (203.2) | 0.109" (2.77) | +/-0.030" (0.76) | +/-10.0% | +1/8" (3.18) -0 | 13.86 |
| 250 | 10"(254) | 0.120"(3.05) | +/-0.040" (1.016) | +/-10.0% | +1/8" (3.18) -0 | - |
| 300 | 12"(304.8) | 0.120"(3.05) | +/-0.040" (1.016) | +/-10.0% | +1/8" (3.18) -0 | - |
ASME BPE Tubing Dimensions & Tolerances
| Size OD | Wall Thickness | OD Tolerance | Length Tolerance | Wall Thickness Tolerance | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| (in) | (mm) | (in) | (mm) | (in) | (mm) | (in) | (mm) | (%) | |||
| ½ | 12.7 | 0.065 | 1.65 | +/-0.005 | +/-0.13 | +⅛, -0 | +3.18, -0 | +/-10.0% | |||
| ¾ | 19.1 | 0.065 | 1.65 | +/-0.005 | +/-0.13 | +⅛, -0 | +3.18, -0 | +/-10.0% | |||
| 1 | 25.4 | 0.065 | 1.65 | +/-0.005 | +/-0.13 | +⅛, -0 | +3.18, -0 | +/-10.0% | |||
| 1½ | 38.1 | 0.065 | 1.65 | +/-0.008 | +/-0.20 | +⅛, -0 | +3.18, -0 | +/-10.0% | |||
| 2 | 50.8 | 0.065 | 1.65 | +/-0.008 | +/-0.20 | +⅛, -0 | +3.18, -0 | +/-10.0% | |||
| 2½ | 63.5 | 0.065 | 1.65 | +/-0.010 | +/-0.25 | +⅛, -0 | +3.18, -0 | +/-10.0% | |||
| 3 | 76.2 | 0.065 | 1.65 | +/-0.010 | +/-0.25 | +⅛, -0 | +3.18, -0 | +/-10.0% | |||
| 4 | 101.6 | 0.083 | 2.11 | +/-0.015 | +/-0.38 | +⅛, -0 | +3.18, -0 | +/-10.0% | |||
| 6 | 152.4 | 0.109 | 2.77 | +/-0.030 | +/-0.76 | +1, -0 | +25.4, -0 | +/-10.0% | |||
Dimension of DIN11850 / EN10357 Dairy Tube
DIN 11850 (German Standard) and EN 10357 (European Norm) specify austenitic stainless steel seamless and welded tubes for hygienic applications, particularly in the food, beverage, pharmaceutical, and chemical industries. These standards ensure high cleanliness, corrosion resistance, and smooth surfaces for sanitary processes.
The wall thickness is relatively thin, making it suitable for low-pressure or normal-temperature applications (such as low-pressure conveying in the food and pharmaceutical industries).
Typical applications: Non-corrosive media or low-pressure scenarios
| Nominal Diameter | Tube OD | Tolerances, OD | Wall Thickness | Telerances, WT | Telerances, Length | Weight |
|---|---|---|---|---|---|---|
| mm | mm | mm | mm | Kg/m | ||
| DN10 | 12 | ±0.12 | 1.0 | ±10% | +3.0 | 0.27 |
| DN15 | 18 | ±0.12 | 1.0 | ±10% | +3.0 | 0.42 |
| DN20 | 22 | ±0.12 | 1.0 | ±10% | +3.0 | 0.51 |
| DN25 | 28 | ±0.12 | 1.0 | ±10% | +3.0 | 0.66 |
| DN32 | 34 | ±0.12 | 1.0 | ±10% | +3.0 | 0.82 |
| DN40 | 40 | ±0.12 | 1.0 | ±10% | +3.0 | 0.97 |
| DN50 | 52 | ±0.2 | 1.0 | ±10% | +3.0 | 1.27 |
Medium wall thickness, combining strength and lightweight, suitable for medium pressure or general industrial applications.
Typical applications: Chemical industry, water treatment and other conventional working conditions.
| Nominal Diameter | Tube OD | Tolerances, OD | Wall Thickness | Tolerances, WT | Tolerances, Length | Length |
|---|---|---|---|---|---|---|
| mm | mm | mm | mm | (m) | ||
| DN10 | 13 | ±0.3 | 1.5 | ±10% | +3.00 | 0.43 |
| DN15 | 19 | ±0.3 | 1.5 | ±10% | +3.00 | 0.66 |
| DN20 | 23 | ±0.3 | 1.5 | ±10% | +3.00 | 0.81 |
| DN25 | 29 | ±0.3 | 1.5 | ±10% | +3.00 | 1.03 |
| DN32 | 35 | ±0.3 | 1.5 | ±10% | +3.00 | 1.26 |
| DN40 | 41 | ±0.3 | 1.5 | ±10% | +3.00 | 1.50 |
| DN50 | 53 | ±0.3 | 1.5 | ±10% | +3.00 | 1.944 |
| DN65 | 70 | ±0.3 | 2.0 | ±10% | +3.00 | 3.43 |
| DN80 | 85 | ±0.3 | 2.0 | ±10% | +3.00 | 4.16 |
| DN100 | 104 | ±0.3 | 2.0 | ±10% | +3.00 | 5.03 |
| DN125 | 129 | ±0.4 | 2.0 | ±10% | +10.00 | 6.36 |
| DN150 | 154 | ±0.4 | 2.0 | ±10% | +10.00 | 7.612 |
| DN200 | 204 | ±0.4 | 2.0 | ±10% | +10.00 | 10.116 |
| DN250 | 254 | ±0.4 | 2.0 | ±10% | +20.00 | 12.555 |
| DN300 | 304 | ±0.4 | 2.0 | ±10% | +20.00 | 15.045 |
The wall thickness is relatively thick, with a higher pressure-bearing capacity, making it suitable for high-pressure, high-temperature or highly corrosive media.
Typical applications: High-pressure steam, strong acids, strong alkalis and other harsh environments.
| Nominal Diameter | Tube OD | Tolerances, OD | Wall Thickness | Tolerances, WT | Tolerances, Length | Weight |
|---|---|---|---|---|---|---|
| mm | mm | mm | mm | Kg/m | ||
| 10 | 14 | ±0.3 | 2.0 | ±10% | +3.00 | 0.60 |
| 15 | 20 | ±0.3 | 2.0 | ±10% | +3.00 | 0.90 |
| 20 | 24 | ±0.3 | 2.0 | ±10% | +3.00 | 1.10 |
| 25 | 30 | ±0.3 | 2.0 | ±10% | +3.00 | 1.40 |
| 32 | 36 | ±0.3 | 2.0 | ±10% | +3.00 | 1.70 |
| 40 | 42 | ±0.3 | 2.0 | ±10% | +3.00 | 2.00 |
| 50 | 54 | ±0.3 | 2.0 | ±10% | +3.00 | 2.60 |
Finish Specifications
The standard mandates that the interior surface must be smooth, non-toxic, non-absorbent, and corrosion-resistant. This is primarily achieved through a mechanical polishing and electropolishing process. The result is an ultra-smooth finish that minimizes the ability for microbes and product particles to adhere, and it allows for effective cleaning and sterilization.
The most common and accepted finish is defined by a maximum Ra (Roughness Average) value. A typical Ra specification for ASTM A270 tubing is ≤ 0.38 µm (15 microinches) or better, often referred to as a “sanitary finish” or “micro-finish.” Some applications, like high-purity pharmaceutical or biotech processes, may require an even smoother finish of ≤ 0.25 µm (10 microinches).
This smooth surface is created by first mechanically abrading the tube with progressively finer abrasives to remove imperfections and weld beads. This is often followed by electropolishing, an electrochemical process that removes a thin layer of surface material. Electropolishing further smooths the surface, removes embedded contaminants, and enhances the natural passive oxide layer, which significantly improves corrosion resistance.
The primary purpose of this meticulously controlled surface is to prevent contamination, facilitate easy and effective cleaning-in-place (CIP) and sterilization-in-place (SIP) procedures, and provide superior corrosion resistance against aggressive cleaning chemicals and process fluids.
Mirror Polished Surface
| Process | RA Micro Inch | RA Micron | ISO Designation |
|---|---|---|---|
| 150 grit | 30-35 | 0.75-0.875 | N6 |
| 150 grit + Electropolish | 12-20 | 0.3-.05 | |
| 180 grit | 20-25 | 0.5-.0625 | |
| 180 grit + Electropolish | 10-16 | 0.25-0.4 | |
| 240 grit | 15-20 | 0.375-0.5 | N5 |
| 240 grit + Electropolish | 8-12 | 0.2-0.3 | |
| 320 grit | 8-12 | 0.2-0.3 | N4 |
| 320 grit + Electropolish | 6-12 | 0.15-0.3 |
Chemical Composition of Stainless Steel Tube
| TUBE GRADES | UNS | Cr | Ni | Mo | C | P | S | Mn | Si |
| TP304 | S30400 | 18.0-20.0 | 8.0-11.0 | – | 0.08 | 0.045 | 0.03 | 2 | 1 |
| TP304L | S30403 | 18.0-20.0 | 8.0-13.0 | – | 0.035 | 0.045 | 0.03 | 2 | 1 |
| TP316 | S3160 | 16.0-18.0 | 11.0-14.0 | 2.0-3.0 | 0.08 | 0.045 | 0.03 | 2 | 1 |
| TP316L | S31603 | 16.0-18.0 | 10.0-14.0 | 2.0-3.0 | 0.035 | 0.045 | 0.03 | 2 | 1 |
Tensile Properties of Stainless Steel Tube
| Material | Heat Treatment | Yield Strength Ksi (MPa), Min. | Tensile Strength Ksi (MPa), Min. | Temperure Min. ℉(℃) | Elongation %, Min |
| ASME SA270 304 | Solution | 30(205) | 75(515) | 1900 (1040) | 35 |
| ASME SA270 304L | Solution | 25(170) | 70(485) | 1900 (1040) | 35 |
| ASME SA270 316 | Solution | 30(205) | 75(515) | 1900(1040) | 35 |
| ASME SA270 316L | Solution | 25(170) | 70(485) | 1900(1040) | 35 |
Sanitary Fittings in Process Piping (Food, Pharma, Dairy, etc.)
In industrial contexts, Sanitary Fittings (or Hygienic Fittings) refer to the specialized components used to connect pipes in systems where purity and cleanliness are critical. They are designed to prevent bacterial growth, allow for complete cleaning, and ensure product integrity.
Key Idea: These are the connectors and pipes themselves, used to build a system for processing sensitive products.
Key Characteristics:
Smooth, Polished Surfaces: Internally, they have a very smooth finish (often measured in Ra micro-inches) to prevent bacteria from clinging and to allow for easy cleaning.
No Crevices or Dead Spaces: They are designed to be flush with the pipe, creating a seamless flow path so that product or cleaning fluids don’t get trapped.
Easy to Disassemble and Clean (CIP/SIP): They are designed for frequent cleaning, often using methods like Clean-in-Place (CIP) or Sterilize-in-Place (SIP).
Material: Almost exclusively made from 304 or 316L Stainless Steel for its corrosion resistance and non-reactivity.
Common Types of Sanitary Fittings:
Clamp Fittings (Tri-Clamp): The most common type, using a three-piece clamp to seal a gasket between two ferrules.
Butt Weld Fittings: Permanently welded to create a perfectly smooth, crevice-free joint. Used where disassembly isn’t needed.
Bevel Seat Fittings: An older style, similar to clamp fittings but with a different gasket and connection system.
DIN/SMS Fittings: Standards more common in Europe, using a threaded nut to compress a gasket.
Common Components:
Elbows (90°, 45°)
Tees
Reducers
Caps
Ferrule (the stub end that gets connected)




