Hygienic tubing systems acc. to DIN EN-10357 A and B




DIN EN-10357: The European standard for hygienic tubes


General information

Since 2014 the DIN EN 10357 series A and B have been the new standards for hygienic tubes; also known as “food tubes” replacing their predecessors DIN 11850 R1 and R2.


DIN EN 10357 series A and B are originally from Germany, however, they are regularly used all over the world such as Europe, Australia and the Middle East, just to mention a few.


These tubes are mainly used in the food & beverage, pharmaceutical and chemical industry and are also often installed in hospitals.


In order to reach the DIN EN 10357 standards’, the tubes has to meet certain requirements regarding their materials, surface treatments, dimensions and tolerances which will ensure a consistent level of quality.


Due to this standardization, these tubes are interchangeable with one another no matter where you are in the world or which supplier you bought the parts from.





In hygienic production lines, fittings and valves are always made of stainless steel, therefore, the types of stainless steel used for EN 10357 A/B tubes are the following:



304 Stainless steel

(AISI 304)

High resistance against rust but susceptible to corrosion from chloride solutions.


316 Stainless steel

(AISI 316)

High resistance against rust and good resistance against chlorides and other industrial solvents.


In terms of material composition these steels are not special, thus, can be produced worldwide with no problem. There are alternate versions of these kind of steels namely 304L and 316L which have better welding properties.

Generally 316 stainless steel is a bit more expensive, but that is not always the case especially in smaller, commonly used diameters the price difference can be negligible.



Seal rings and gaskets come in a lot of materials, for instance, EPDM, Viton, PTFE and much more. In this case, it is critical to choose the right one since these materials have very different properties.


Tube sizes:


EN-10357 Series A (DIN 11850 Range 2) tubes
Size (DN) Outside diameter (mm). Thickness (mm).
10 13 1,50
15 19 1,50
20 23 1,50
25 29 1,50
32 35 1,50
40 41 1,50
50 53 1,50
65 70 2,00
80 85 2,00
100 104 2,00
125 129 2,00
150 154 2,00
200 204 2,00


EN-10357 Series B (DIN 11850 Range 1) tubes
Size (DN) Outside diameter (mm). Thickness (mm).
10 12 1,00
15 18 1,00
20 22 1,00
25 28 1,00
32 34 1,00
40 40 1,00
50 52 1,00


Fittings for DIN EN 10357 series A tubes:


1. DIN 11851 Unions

DIN 11851 is a standard for a hygienic union consisting of four parts, which are fully compatible with EN 10357 series A tubes.

This type of union is used in product lines that require regular assembling and disassembling

You only one piece of tool: a spanner wrench.



The four different parts of a DIN 11851 connection:

1. A male threaded part

2. A conical shaped liner

3. A D-shaped seal ring

4. A round (slotted) nut




By tightening the nut, the seal ring is clamped by the liner in a groove of the male part. This creates a very reliable, clean and fluid-tight connection.




Not only tubes can be assembled by a DIN 11851 connection; there are also a lot of fittings and valves available that have a male threaded part or a liner already in place, which makes it possible to assemble/disassemble product lines very quickly.

This makes the cleaning of pipes and fittings very easy which otherwise would be a time-consuming task.






2. DIN 11852 weld fittings

Out of all the tube connection methods, the welded connection is the cheapest and the most reliable one.


There is a complete range of hygienic weld fittings and valves available for use with EN 10357 B tubes; this range is standardized as DIN 11852.

The range contains tees, reduced tees, bends (45°, 90°, 180°), y-pieces and reducers. With these parts you can design every welded process line you need.

DIN 11852 fittings are readily available in almost every country, usually in diameters up to DN150 and in both materials: AISI 304L and AISI 316L.





3. DIN 32676 tri clamp unions

Tri clamps union is used when a tubing system has to be assembled and disassembled very often and very quickly. Mostly there are no tools needed to tighten the connection, you can simply open or close the clamp ring by turning the butterfly nut. There are also clamp rings available with hexagonal nuts; then you need a wrench.

A tri clamp coupling consists of:


1. Two identical conical shaped ferrules with a seal groove

2. A seal ring

3. A clamp ring with a conical shaped inner ring.






























4. DIN 11864 Flange connections

DIN 11864 flanges are used in process systems with very high hygienic demands, like biotechnology, pharmaceutical, cosmetical and chemical industries, nevertheless, they are also used in food and beverage production plants.

DIN 11864 flanges are only available in AISI 316L.

A connection is made by using a flange with a groove, a flange with notch and an O-shaped seal ring. By tightening the bolts, the seal ring is pushed exactly in the groove and it will be locked by the other flange.