-
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 tubing is selected for milk, cream, whey, and other dairy-product transfer between process equipment. This page focuses on dairy-line procurement: the buyer should specify the product and cleaning media, grade, tube dimensions, internal finish, joint type, inspection requirements, and applicable sanitary standard.
The suitability of 304/304L or 316/316L depends on the actual product, cleaning conditions, and system design. Confirm how the tube connects to pasteurizers, separators, tanks, and filling equipment, and how the completed line will be cleaned and inspected. For a specific tube standard, see ASTM A270, EN 10357, or AS 1528.1. For broader food and beverage uses, see food-grade tubing.
Dairy-line handover: Include the connection standard and mating ferrule dimensions, product-contact finish target, weld-joint treatment, cleaning cycle and required records in the RFQ. Ask which checks will be documented for the supplied tubing, such as dimensions, surface roughness and material traceability; define any additional inspection in the purchase specification.
ASTM A270 Tube Size Reference for Dairy Lines
The dimensions below are a reference when an ASTM A270 tube is considered for a dairy process line. Confirm the selected size, grade, finish, connection method, cleaning conditions, and documentation in the purchase specification. The ASTM A270 product page covers the standard-specific tube details.
| 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% | |||
DIN 11850 and EN 10357 Sizes for Dairy Processing
For dairy equipment that specifies DIN 11850 or EN 10357, check tube dimensions against the mating fittings, processing equipment, and cleaning arrangement. Confirm the applicable series and finish before placing an order. Review the DIN 11850 and EN 10357 pages for the corresponding standard-specific information.
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)