New and Old DIN Designations

Over the years, many DIN standards were integrated into the ISO standards, and thus also a part of the EN standards. In the cource of the revision of the European standards serveral DIN standards were withdrawn and replaced by DIN ISO EN and DIN EN.

The standards used in the past such as the DIN 17121, DIN 1629, DIN 2448 and the DIN 17175 have since been mostly replaced by Euronorms. The Euronorms clearly distinguish the pipe's area of application. Consequently different standards now exist for pipes used as construction materials, pipelines or for mechanical engineering applications.

This distinction was not as clear in the past. For example, the old St.52.0 quality was derived from the DIN 1629 standard which was intended for pipeline systems and mechanical engineering applications. This quality was also often used for steel structures, however.
The info below explains the main standards and steel qualities under the new system of standards.

Seamless Pipes and Tubes for Pressure Applications

The EN 10216 Euronorm replaces the old DIN 17175 and 1629 standards. This standard is designed for pipes used in pressure applications, such as a pipeline. This is why the associated steel qualities are designated by the letter P for 'Pressure'. The value that follows this letter designates the minimum yield strength. The subsequent letter designations provide additional information.

The EN 10216 comprises several parts. The parts that are relevant to us are as follows..

EN 10216 Part 1.. non-alloy pipes with specified properties at room temperature
EN 10216 Part 2.. non-alloy pipes with specified properties at higher temperatures
EN 10216 Part 3.. alloy pipes made from fine-grained steel for any temperature

Some examples..

EN 10216-1, Quality P235TR2 (formerly DIN 1629, St.37.0)
P = Pressure
235 = minimum yield strength in N/mm2
TR2 = quality with specified properties relating to aluminum content, impact values and inspection and test requirements. (In contrast to TR1, for which this is not specified).
EN 10216-2, Quality P235 GH (formerly DIN 17175, St.35.8 Cl. 1, boiler pipe)
P = Pressure
235 = minimum yield strength in N/mm2
GH = tested properties at higher temperatures
EN 10216-3, Quality P355 N (more or less equivalent to DIN 1629, St.52.0)
P = Pressure
355 = minimum yield strength in N/mm2
N = normalized*

Normalized is defined as.. normalized (warm) rolled or standard annealing (at a min temperature of 930°C). This applies to all qualities designated by the letter 'N' in the new Euro Standards.

Pipes.. the following standards are replaced by DIN EN

Pipes for pressure applications

OLD STANDARD
Execution	Norm	Steel grade
Welded	DIN 1626	St.37.0
Welded	DIN 1626	St.52.2
Seamless	DIN 1629	St.37.0
Seamless	DIN 1629	St.52.2
Seamless	DIN 17175	St.35.8/1
Seamless	ASTM A106*	Grade B
Seamless	ASTM A333*	Grade 6

NEW STANDARD
Execution	Norm	Steel grade
Welded	DIN EN 10217-1	P235TR2
Welded	DIN EN 10217-3	P355N
Seamless	DIN EN 10216-1	P235TR2
Seamless	DIN EN 10216-3	P355N
Seamless	DIN EN 10216-2	P235GH
Seamless	DIN EN 10216-2	P265GH
Seamless	DIN EN 10216-4	P265NL

ASTM standards will remain valid and will not be replaced by Euronorms in the near future

Description of DIN EN 10216 (5 parts) and 10217 (7 parts)

DIN EN 10216-1
Seamless steel tubes for pressure purposes - Technical delivery conditions. Part 1.. Non-alloy steel tubes with specified room temperature properties Specifies the technical delivery conditions for two qualities, T1 and T2, of seamless tubes of circular cross section, with specified room temperature properties, made of non-alloy quality steel...

DIN EN 10216-2
Seamless steel tubes for pressure purposes - Technical delivery conditions - Part 2.. Non alloy and alloy steel tubes with specified elevated temperature properties; German version EN 10216-2:2002+A2:2007. The document specifies the technical delivery conditions in two test categories for seamless tubes of circular cross section, with specified elevated temperature properties, made of non-alloy and alloy steel.

DIN EN 10216-3
Seamless steel tubes for pressure purposes - Technical delivery conditions - Part 3.. Alloy fine grain steel tubes. Specifies the technical delivery conditions in two categories for seamless tubes of circular cross section, made of weldable alloy fine grain steel...

DIN EN 10216-4
Seamless steel tubes for pressure purposes - Technical delivery conditions - Part 4.. Non-alloy and alloy steel tubes with specified low temperature properties specifies the technical delivery conditionsin two categories for seamless tubes of circular crossection, made with specified low temperature properties, made of non-alloy and alloy steel...

DIN EN 10216-5
Seamless steel tubes for pressure purposes - Technical delivery conditions - Part 5.. Stainless steel tubes; German version EN 10216-5:2004, Corrigendum to DIN EN 10216-5:2004-11; German version EN 10216-5:2004/AC:2008.
This Part of this European Standard specifies the technical delivery conditions in two test categories for seamless tubes of circular cross-section made of austenitic (including creep resisting steels) and austenitic-ferritic stainless steel which are applied for pressure and corrosion resisting purposes at room temperature, at low temperatures or at elevated temperatures. It is important that the purchaser, at the time of enquiry and order, takes in account the requirements of the relevant national legal regulations for the intended application.

DIN EN 10217-1
Welded steel tubes for pressure purposes - Technical delivery conditions - Part 1.. Non-alloy steel tubes with specified room temperature properties. This Part of EN 10217 specifies the technical delivery conditions for two qualities TR1 and TR2 of welded tubes of circular cross section, made of non-alloy quality steel and with specified room tempe...

DIN EN 10217-2
Welded steel tubes for pressure purposes - Technical delivery conditions - Part 2.. Electric welded non-alloy and alloy steel tubes with specified elevated temperature properties specifies the technical delivery conditions in two test categories of electric welded tubes of circular cross section, with specified elevated temperature properties, made of non-alloy and alloy steel...

DIN EN 10217-3
Welded steel tubes for pressure purposes - Technical delivery conditions - Part 3.. Alloy fine grain steel tubes specifies the technical delivery conditions for welded tubes of circular cross section, made of weldable non-alloy fine grain steel...

DIN EN 10217-4
Welded steel tubes for pressure purposes - Technical delivery conditions - Part 4.. Electric welded non-alloy steel tubes with specified low temperature properties specifies the technical delivery conditions in two test categories of electric welded tubes of circular cross section, with specified low temperature properties, made of non-alloy steel...

DIN EN 10217-5
Welded steel tubes for pressure purposes - Technical delivery conditions - Part 5.. Submerged arc welded non-alloy and alloy steel tubes with specified elevated temperature properties specifies the technical delivery conditions in two test categories of submerged arc welded tubes of circular cross section, with specified elevated temperature properties, made of non-alloy and alloy...

DIN EN 10217-6
Welded steel tubes for pressure purposes - Technical delivery conditions - Part 6.. Submerged arc welded non-alloy steel tubes with specified low temperature properties specifies the technical delivery conditions in two test categories of submerged arc welded tubes of circular cross section, with specified low temperature properties, made of non-alloy steel...

DIN EN 10217-7
Welded steel tubes for pressure purposes - Technical delivery conditions - Part 7.. Stainless steel tubes specifies the technical delivery conditions in two test categories for welded tubes of circular cross-section made of austenitic and austenitic-ferritic stainless steel which are applied for pressure...

Pipes for construction applications

OLD STANDARD
Execution	Norm	Steel grade
Welded	DIN 17120	St.37.2
Welded	DIN 17120	St.52.3
Seamless	DIN 17121	St.37.2
Seamless	DIN 17121	St.52.3

NEW STANDARD
Execution	Norm	Steel grade
Welded	DIN EN 10219-1/2	S235JRH
Welded	DIN EN 10219-1/2	S355J2H
Seamless	DIN EN 10210-1/2	S235JRH
Seamless	DIN EN 10210-1/2	S355J2H

Description of DIN EN 10210 and 10219 (each 2 parts)

DIN EN 10210-1
Hot finished structural hollow sections of non-alloy and fine grain steels - Part 1.. Technical delivery conditions. This part of this European Standard specifies technical delivery conditions for hot finished hollow sections of circular, square, rectangular or elliptical forms and applies to hollow sections formed...

DIN EN 10210-2
Hot finished structural hollow sections of non-alloy and fine grain steels - Part 2.. Tolerances, dimensions and sectional properties. This part of EN 10210 specifies tolerances for hot finished circular, square, rectangular and elliptical structural hollow sections, manufactured in wall thicknesses up to 120 mm, in the following siz...

DIN EN 10219-1
Cold formed welded structural hollow sections of non-alloy and fine grain steels - Part 1.. Technical delivery conditions. This part of this European Standard specifies the technical delivery conditions for cold formed welded structural hollow sections of circular, square or rectangular forms and applies to structural hol...

DIN EN 10219-2
Cold formed welded structural hollow sections of non-alloy and fine grain steels - Part 2.. Tolerances, dimensions and sectional properties. This part of EN 10219 specifies tolerances for cold formed welded circular, square and rectangular structural hollow sections, manufactured in wall thicknesses up to 40 mm, in the following size range...

Pipes for pipeline applications

OLD STANDARD
Execution	Norm	Steel grade
Welded	API 5L	Grade B
Welded	API 5L	Grade X52
Seamless	API 5L	Grade B
Seamless	API 5L	Grade X52

NEW STANDARD
Execution	Norm	Steel grade
Welded	DIN EN 10208-2	L245NB
Welded	DIN EN 10208-2	L360NB
Seamless	DIN EN 10208-2	L245NB
Seamless	DIN EN 10208-2	L360NB

API standards will remain valid and will not be replaced by Euronorms in the near future

Description of DIN EN 10208 (3 parts)

DIN EN 10208-1
Steel pipes for pipelines for combustible fluids - Technical delivery conditions - Part 1.. Pipes of requirement class A. This European Standard specifies the technical delivery conditions for seamless and welded steel pipes for the on land transport of combustible fluids primarily in gas supply systems but excluding pip...

DIN EN 10208-2
Steel pipes for pipelines for combustible fluids - Technical delivery conditions - Part 2.. Pipes of requirement class B. This European Standard specifies the technical delivery conditions for seamless and welded steel pipes for the on land transport of combustible fluids primarily in gas supply systems but excluding pip...

DIN EN 10208-3
Steel pipes for pipe lines for combustible fluids - Technical delivery conditions - Part 3.. Pipes of class C. Specifies the technical delivery conditions for unalloyed and alloyed (except stainless) seamless and welded steel pipes. It includes quality and testing requirements overall higher than those specifi...

Fittings.. the following standards are replaced by DIN EN 10253

DIN 2605 Elbows
DIN 2615 Tees
DIN 2616 Reducers
DIN 2617 Caps

DIN EN 10253-1
Butt-welding pipe fittings - Part 1.. Wrought carbon steel for general use and without specific inspection requirements. The document specifies requirements for steel butt-welding fittings, namely elbows and return bends, concentric reducers, equal and reducing tees, dished and caps.

DIN EN 10253-2
Butt-welding pipe fittings - Part 2.. Non alloy and ferritic alloy steels with specific inspection requirements; German version EN 10253-2. This European Standard specifies in two parts the technical delivery conditions for steel butt welding pipe fittings (elbows, return bends, concentric and eccentric reducers, equal and reducing tees, and caps) which are intended for pressure purposes and for the transmission and distribution of fluids and gases. The part 1 covers fittings of unalloyed steels without specific inspection requirements. The part 2 covers fittings with specific inspection requirements and offers two ways for determining the resistance to internal pressure of the fitting.

DIN EN 10253-3
Butt-welding pipe fittings - Part 3.. Wrought austenitic and austenitic-ferritic (duplex) stainless steels without specific inspection requirements; German version EN 10253-3. This part of EN 10253 specifies the technical delivery requirements for seamless and welded butt-welding fittings made of austenitic and austenitic-ferritic (duplex) stainless steels and delivered without specific inspection.

DIN EN 10253-4
Butt-welding pipe fittings - Part 4.. Wrought austenitic and austenitic-ferritic (duplex) stainless steels with specific inspection requirements; German version EN 10253-4. This European Standard specifies the technical delivery requirements for seamless and welded butt-welding fittings (elbows, concentric and eccentric reducers, equal and reducing tees, caps) made of austenitic and austenitic-ferritic (duplex) stainless steel which are intended for pressure and corrosion resisting purposes at room temperature, at low temperature or at elevated temperatures. It specifies.. the type of fittings, the steel grades, the mechanical properties, the dimensions and tolerances, the requirements for inspection and testing, the inspection documents, the marking, the handling and packaging.

NOTE.. In the case of a harmonised supporting standard for materials, presumption of conformity to the Essential Requirement(s) (ESRs) is limited to technical data of materials in the standard and does not presume adequacy of the material to a specific item of equipment. Consequently the technical data stated in the material standard should be assessed against the design requirements of this specific item of equipment to verify that the ESRs of the Pressure Equipment Directive (PED) are satisfied. Unless otherwise specified in this European Standard the general technical delivery requirements in DIN EN 10021 apply.

Flanges.. the following standards are replaced by DIN EN 1092-1

DIN 2513 Spigot and Recess flanges
DIN 2526 Flange facings
DIN 2527 Blind flanges
DIN 2566 Threaded flanges
DIN 2573 Flat flange for welding PN6
DIN 2576 Flat flange for welding PN10
DIN 2627 Weld Neck flanges PN 400
DIN 2628 Weld Neck flanges PN 250
DIN 2629 Weld Neck flanges PN 320
DIN 2631 until DIN 2637 Weld Neck flanges PN2.5 until PN100
DIN 2638 Weld Neck flanges PN 160
DIN 2641 Lapped flanges PN6
DIN 2642 Lapped flanges PN10
DIN 2655 Lapped flanges PN25
DIN 2656 Lapped flanges PN40
DIN 2673 Loose flange and ring with neck for welding PN10

DIN EN 1092-1
Flanges and their joints - Circular flanges for pipes, Valves, fittings and accessories, PN designated - Part 1.. Steel flanges; German version EN 1092-1:2007. This European standard specifies requirements for circular steel flanges in PN designations PN 2,5 to PN 400 and nominal sizes from DN 10 to DN 4000. This standard specifies the flange types and their facings, dimensions, tolerances, threading, bolt sizes, flange face surface finish, marking, materials, pressure / temperature ratings and flange masses.

DIN EN 1092-2
Circular flanges for pipes, Valves, fittings and accessories, PN designated - Part 2.. Cast iron flanges. The document specifies requirements for circular flanges made from ductile, grey and malleable cast iron for DN 10 to DN 4000 and PN 2,5 to PN 63. It also specifies the types of flanges and their facings, dimensions and tolerances, bolt sizes, surface finish of jointing faces, marking, testing, quality assurance and materials together with associated pressure/temperature (p/T) ratings.

DIN EN 1092-3
Flanges and their joints - Circular flanges for pipes, Valves, fittings and accessories, PN designated - Part 3.. Copper alloy flanges. This document specifies requirements for circular copper alloy flanges in PN designations from PN 6 to PN 40 and nominal sizes from DN 10 to DN 1800.

DIN EN 1092-4
Flanges and their joints - Circular flanges for pipes, Valves, fittings and accessories, PN designated - Part 4.. Aluminium alloy flanges. This standard specifies requirements for PN designated circular flanges for pipes, Valves, fittings and accessories made from aluminium alloy in the range of DN 15 to DN 600 and PN 10 to PN 63. This standard specifies the types of flanges and their facings, dimensions and tolerances, bolt sizes, surface finish of faces, marking and materials together with associated P/T ratings. The flanges are intended to be used for pipework as well as for pressure vessels.