Introduction.

EN 10216-4 is a European standard that specifies the technical delivery conditions for seamless steel tubes for pressure purposes. The standard covers a range of steel grades and types of tubes, including those used in high temperature and high-pressure applications.

Seamless steel tubes are a popular choice for applications where high strength, durability, and reliability are required. They are made from a solid billet of steel that is heated and then formed into a tube shape without any welding or seams. This process results in a tube with a uniform and consistent wall thickness, which provides greater strength and durability compared to welded tubes.

EN 10216-4 introduces seamless steel tubes for pressure purposes that are made from alloyed and unalloyed steels with specified elevated temperature properties. These tubes are intended for use in high temperature applications such as steam boiler and pressure vessel construction.

The standard specifies the chemical composition, mechanical properties, and testing requirements for the seamless steel tubes. It also includes information on the dimensions, tolerances, and surface finish of the tubes.

The introduction of seamless steel tubes to EN 10216-4 provides a standardized approach to the manufacturing and testing of these tubes for pressure applications. This helps ensure that the tubes meet the required performance standards and can be used safely and reliably in high temperature and high-pressure environments.

Seamless steel tubes for pressure purposes – Technical delivery conditions – Part 4: Non-alloy and alloy steel tubes with specified low temperature properties

Foreword
This document (EN 10216-4:2002) has been prepared by Technical Committee ECISS/TC 29, "Steel tubes and fittings forsteel tubes", the secretariat of which is held by UNI.This European Standard shall be given the status of a national standard, either by publication of an identical text or byendorsement, at the latest by November withdrawn at the latest by November 2002.This document has been prepared under a mandate given to CEN by the European Commission and the EuropeanFree Trade Association, and supports essential requirements of EU Directive(s).For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this document. OtherParts of EN 10216 are:
Part 1:Non-alloy steel tubes with specified room temperature properties.
Part 2 :Non-alloy and alloy steels tubes with specified elevated temperature properties
Part 3 :Alloy fine grain steel tubes
Part 5 :Stainless steel tubes
Another European Standard series covering tubes for pressure purposes is: EN 10217: Welded steel tubes for pressure purposes

Foreword to amendment A1
This document (EN 10216-4:2002/A1:2004) has been prepared by Technical Committee ECISS /TC 29"Steel tubes and fittings for steel tubes", the secretariat of which is held by UNI.This European Standard shall be given the status of a national standard, either by publication of an identicaltext or by endorsement, at the latest by September 2004, and conflicting national standards shall bewithdrawn at the latest by September 2004.This document has been prepared under a mandate given to CEN by the European Commission and theEuropean Free Trade Association, and supports essential requirements of EU Directive 97/23/EC.For relationship with EU Directive 97/23/EC, see informative Annex ZA, which is an integral part of this document.

1 SCOPE
This Part of EN 10216 specifies the technical delivery conditions in two test categories for seamless tubes of circular cross section, with specified low temperature properties, made of non-alloy and alloy steel.

2 NORMATIVE REFERENCES
This European Standard incorporates by date or undated reference, provisions from other publications.
These normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For date references, subsequent amendments to or revisions of, any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments). The requirements of this European Standard rule when they differ from those in the standards documents referred to below:
EN 10002-1, Metallic materials – Tensile testing – Part 1: Method of test (at ambient temperature).
EN 10020, Definitions and classification of grades of steel.
EN 10021, General technical delivery requirements for steel and iron products.
EN 10027-1, Designation systems for steels – Part 1 : Steel names, principle symbols.
EN 10027-2, Designation systems for steels Part 2 : Numerical systems. EN 10045-1, Metallic materials – Charpy impact test – Part 1: Test method. EN 10052, Vocabulary of heat treatment terms for ferrous products.
EN 10204, Metallic products – Types of inspection documents.
ENV 10220, Seamless and welded steel tubes – Dimensions and masses per unit length
EN 10233, Metallic materials – Tubes – Flattening test.
EN 10234, Metallic materials – Tubes – Drift expanding test. EN 10236, Metallic materials – Tubes – Ring expanding test. EN 10237, Metallic materials – Tubes – Ring tensile test.
EN 10246-1, Non-Destructive Testing of steel tubes Part 1 : Automatic electromagnetic testing of seamless and welded (except submerged arc welded) ferromagnetic steel tubes for verification of hydraulic leak- tightness.
EN 10246-5, Non-Destructive Testing of steel tubes Part 5: Automatic full peripheral magnetic transducer/flux leakage testing of seamless and welded (except submerged arc-welded) ferromagnetic steel tubes for the detection of longitudinal imperfections.
EN 10246-6, Non-Destructive Testing of steel tubes – Part 6: Automatic full peripheral ultrasonic testing of seamless steel tubes for the detection of transverse imperfections.
EN 10246-7, Non-Destructive Testing of steel tubes – Part 7 : Automatic full peripheral ultrasonic testing of seamless and welded (except submerged arc welded) steel tubes for the detection of longitudinal imperfections.
EN 10246-14, Non-Destructive Testing of steel tubes – Part 14:Automatic ultrasonic testing of seamless and welded (except submerged arc welded) steel tubes for the detection of laminar imperfections.
EN 10256, Non-Destructive Testing of steel tubes – Qualification and competence of level 1 and level 2 NDT personnel.
EN ISO 377, Steel and steel products – Location and preparation of samples and test pieces for mechanical testing (ISO 377:1997)
EN ISO 2566-1, Steel – Conversion of elongation values Part 1: Carbon and low-alloy steels (ISO 2566- 1:1984)
prEN 10168 1) Iron and steel products – Inspection documents – List of information and description
prEN 10266 1) Steel tubes, fittings and structural hollow sections – Symbols and definition of terms for use in product standards
ISO 14284, Steel and iron – Sampling and preparation of samples for the determination of chemical composition
CR 10260, Designation systems for steel – Additional symbols
CR 10261, ECISS Information Circular IC 11 – Iron and steel – Review of available methods of chemical analysis.

3 TERMS AND DEFINITIONS
For the purposes of this Part of EN 10216, the terms and definitions of EN 10020, EN 10021, EN 10052, prEN 10266 and the following apply:
3.1 test category
classification that indicates the extent and level of inspection and testing.
3.2 employer
organisation for which a person works on a regular basis. NOTE The employer may be either the tube manufacturer or supplier or a third party organisation providing Non- Destructive Testing (NDT) services.

4 SYMBOLS
For the purposes of this Part of EN 10216, the symbols given prEN 10266 and the following apply: TC test category

5 CLASSIFICATION AND DESIGNATION
5.1 Classification
In accordance with the classification system in EN 10020, the steel grades P 215NL, P 255QL and P265NL are classified as non-alloy quality steels and the other steel grades are classified as alloy special steels.
5.2 Designation
5.2.1 For the tubes covered by this Part of EN 10216 the steel designation consists of: the number of this Part of EN 10216 ; plus either: the steel name in accordance with EN 10027-1 and CR 10260; or: the steel number allocated in accordance with EN 10027-2.
5.2.2 The steel name of non-alloy steel grades is designated by:
the capital letter P for pressure purposes; the indication of the specified minimum yield strength at room temperature, expressed in MPa (see Table 4); the symbol of the heat treatment for the steel grade concerned (see Table 1); the symbol L for low temperature.
5.2.3 The steel name of alloy-steel grades is designated by the chemical composition (see Table 2) and the symbols for the heat treatment, where specified in column 1 and footnote a) of Table 1

6 INFORMATION TO BE SUPPLIED BY THE PURCHASER
6.1 Mandatory information
The following information shall be supplied by the purchaser at the time of enquiry and order:
a) the quantity (mass or total length or number);
b) the term "tube";
c) the dimensions (outside diameter D and wall thickness T) (see Table 6);
d) the designation of the steel grade in accordance with this Part of EN 10216 (see 5.2);
e) the test category for non-alloy steel(see 9.3).
6.2 Options
A number of options are specified in this Part of EN 10216 and these are listed below. In the event that the purchaser does not indicate a wish to implement any of these options at the time of enquiry and order, the tubes shall be supplied in accordance with the basic specification (see 6.1).
1) cold finishing (see 7.3.2);
2) restriction on copper and tin content (see Table 2);
3) product analysis (see 8.2.2);
4) selection of leak-tightness test method (see 8.4.2.1);
5) Non-Destructive Testing for test category 2 tubes for detection of transverse imperfections (see 8.4.2.2);
6) Non-Destructive Testing for test category 2 tubes for detection of laminar imperfections (see 8.4.2.2);
7) special ends preparation (see 8.6);
8) exact lengths (see 8.7.3);
9) the type of inspection document other than the standard document (see 9.2.1);
10) test pressure for hydrostatic leak-tightness test (see 11.8.1);
11) wall thickness measurement away from the ends (see 11.9);
12) Non-Destructive Testing method (see 11.11.1);
13) additional marking (see 12.2);
14) protection (see 13);
6.3 Example of an order
50 t of seamless tube with an outside diameter of 168,3 mm, a wall thickness of 4,5 mm in accordance with EN 10216-4, made of steel grade P265NL, test category 1, with a 3.1.C inspection certificate in accordance with EN 10204: 50 t – Tube – 168,3 x 4,5 – EN 10216-4 – P265NL – TC1 – Option 9: 3.1.C

7 MANUFACTURING PROCESS
7.1 Steelmaking process
The steelmaking process is at the discretion of the manufacturer.
7.2 Deoxidation process
Steels shall be fully killed.
7.3 Tube manufacture and delivery conditions
7.3.1 All NDT activities shall be carried out by qualified and competent level 1,2 and/or 3 personnel authorised to operate by the employer.
The qualification shall be in accordance with EN 10256 or, at least, an equivalent to it.
It is recommended that the level 3 personnel be certified in accordance with EN 473 or, at least, an equivalent to it.
The operating authorisation issued by the employer shall be in accordance with a written procedure. NDT operations shall be authorised by level 3 NDT individual approved by the employer.
EXAMPLE The definition of level 1, 2 and 3 can be found in appropriate Standards, e.g. EN 473 and EN 10256
7.3.2 The tubes shall be manufactured by a seamless process.
Unless option 1 is specified, the tubes may be either hot or cold finished at the discretion of the manufacturer. The terms hot finished and cold finished apply to the condition of the tube before it is heat treated in accordance with 7.3.3.
Option 1: The tubes shall be cold finished before heat treatment.
7.3.3 The tubes shall be supplied in the relevant heat treatment conditions as specified in Table 1.

Table 1 Delivery conditions

Steel grade

Heat treatment a b

Normalising temperature

Tempering temperature°C

Quenching and tempering

Steel name

Steel number

Hardening temperature° C

Cooling medium ^c

Tempering temperature°C

P215NL

1.0451

900 to 940

—

P255QL

1.0452

+QT

—

890 to 930

Water or oil

600 to 680

P265NL

1.0453

880 to 940

—

26CrMo4-2

1.7219

+QT

—

830 to 860

Water or oil

600 to 680

11 MnNi5-3

1.6212

+N d

890 to 940

(580 to 640)

—

13 MnNi6-3

1.6217

+N d)

890 to 940

(580 to 640)

—

12Ni14

1.5637

+NT

830 to 880

580 to 640

—

+QT

—

820 to 880

Water or oil

580 to 660

X12Ni5

1.568

+NT

800 to 850

580 to 640

—

+QT

—

800 to 850

Water or oil

580 to 660

X10Ni9

1.5682

+N+NT

880 to 915 + 775 to 805

565 to 605^e

—

+QT f

(880 to 930)

—

770 to 820

water or oil

540 to 600

^aN = Normalising ; QT = Quenching and Tempering; NT = Normalising and Tempering
^bWhere two types of heat treatment are specified for a steel grade, the application depends on wall thickness and T/D ratio. The decision is left to the manufacturer but shall be reported in the inspection document.
^cWhen choosing the cooling medium the influence of other parameters, such as dimensions and quenching temperature, on properties and crack susceptibility should be taken into account. Other cooling media such as synthetic quenchants may also be used.
^dTempering can occasionally be necessary after normalising; The decision shall be left to the discretion of the manufacturer but shall be stated to the customer at the time of enquiry and order. Steel tubes treated in such a way shall be designated by the steel name supplemented by the symbol +NT .
^eCooling at still air or accelerated cooling.
^fAn additional prenormalising treatment, in the temperature range indicated may be necessary for this grade. In such a case the manufacturer shall inform the purchaser.

8 REQUIREMENTS
8.1 General
When supplied in a delivery condition indicated in clause 7.3 and inspected in accordance with clauses 9, 10 and 11, the tubes shall conform to the requirements of this Part EN 10216.
In addition, the general technical delivery requirements specified in EN 10021 shall apply. Tubes shall be suitable for hot and cold bending provided the bending is carried out in an appropriate manner.
8.2 Chemical composition
8.2.1 Cast analysis
The cast analysis reported by the steel producer shall apply and conform to with the requirements of Table 2.
NOTE: When welding tubes produced in accordance with this Part of EN 10216, account should be taken of the fact that the behaviour of the steel during and after welding is dependent not only on the steel, but also on the applied heat treatment and the conditions of preparing for and carrying out the welding.
8.2.2 Product analysis
Option 3: A product analysis for the tubes shall be supplied.
Table 3 specifies the permissible deviations of the product analysis from the specified limits on cast analysis given in Table 2 are specified in Table 3.
8.3 Mechanical properties
The mechanical properties of the tubes shall conform to the requirements in Tables 4 and 5 and in 11.3 to 11.6.

Table 2 Chemical composition (cast analysis)^a, in % by mass

Steel grade

Pmax

Smax

Al^b
total min

Cu^c
max

Nb max

Ti max

Vmax

Steel name

Steel number

P215NL

1.0451

≤0.15

≤0.35

0.40 to 1.20

0.025

0.02

≤0.3

≤0.08

0.02

0.3

0.01

0.04

0.02

P255QL

1.0452

≤0.17

≤0.35

0.40 to 1.20

0.025

0.02

≤0.3

≤0.08

0.02

0.3

0.01

0.04

0.02

P265NL

1.0453

≤0.20

≤0.4

0.60 to 1.40

0.025

0.02

≤0.3

≤0.08

0.02

0.3

0.01

0.04

0.02

26CrMo4-2

1.7219

0.22 to 0.29

≤0.35

0.50 to 0.80

0.025

0.02

0.90 to 1.20

—

0.15 to 0.3

—

0.3

—

11 MnNi5-3

1.6212

≤0.14

≤0.5

0.70 to 1.50

0.025

0.015

—

0.30^d to 0.80

—

0.02

0.3

0.05

—

0.05

13 MnNi6-3

1.6217

≤0.16

≤0.5

0.85 to 1.70

0.025

0.015

—

0.30^d to 0.85

—

0.02

0.3

0.05

—

0.05

12Ni14

1.5637

≤0.15

0.15 to 0.35

0.30 to 0.80

0.025

0.01

—

3.25 to 3.75

—

0.3

—

0.05

X12Ni5

1.568

≤0.15

≤0.35

0.30 to 0.80

0.02

0.01

—

4.5 to 5.3

—

0.3

—

0.05

X10Ni9

1.5682

≤0.13

0.15 to 0.35

0.30 to 0.80

0.02

0.01

—

8.5 to 9.5

≤0.1

—

0.3

—

0.05

^a Element not included in this table shall not be intertionally added to the steel without the agreement of the purchaser, except for elements which may be added for finishing the cast. All appropricate measures shall be taken to
prevent the addition of undesirable elements from scrap or other materials used in the steel making process.
^b By agreement between purchaser and manufacturer, aluminium may be replaced by other elements having a similar effect.
^c Option 2: in order to ficilicate subsequent forming operation, an agreed maximum copper content lower than indicated and an agreed specified maximum tin content shall apply.
^d The lower limit for the nickel content may be reduced to not less than 0.15% for tubes with thickness not exceeding 10mm

Table 3 Permissible deviations of the product analysis from specified limits on cast analysis given in Table 2

Element

Limiting value for the cast analysis in accordance with Table 2 % by mass

Permissible deviation of the product analysis % by mass

≤0,29

±0,02

≤0,40

±0,05

> 0, 40 ≤ 0.50

+0,06

≤1,70

+0,10

– 0,05

≤0,025

+ 0,005

≤0,015

+ 0,003

> 0,015 ≤ 0.020

+ 0,005

≥0,020

-0,005

≤1,20

±0,10

≤0,30

+0,05

≤0,30

±0,05

≤0,05

+0,005

≤0,85

±0,05

0,85 ÷3.75

±0,07

3,75÷5.30

±0,10

5,30÷9.50

±0,15

≤0.040

+ 0,01

≤0,05

+ 0,01

Table 4 Mechanical properties at room temperature for wall thickness up to and including 40 mm

Steel grade

Upper yield strength or proof strength
ReH or Rp0,2 min MPa *

Tensile strength Rm
MPa *

Elongation A min % a

Steel name

Steel number

P215NL

1.0451

215^b

360 to 480

P255QL

1.0452

255

360 to 490

P265NL

1.0453

265^c

410 to 570

26CrMo4-2

1.7219

440

560 to 740

11 MnNi5-3

1.6212

285

410 to 530

13 MnNi6-3

1.6217

355

490 to 610

12Ni14

1.5637

345

440 to 620

X12Ni5

1.568

390

510 to 710

X10Ni9

1.5682

510

690 to 840

^a l = longitudinal   t = transverse.
^b For wall thickness   10 mm.
^cFor wall thickness   25 mm
^* 1 MPA = 1N/mm2

Table 5 Minimum impact energy

Steel grade

Wall thickness T mm

Orientation of test pieces
with respect to tube axis

Minimum average impact energy KVJ at a temperature of °C

Steel name

Steel number

-196

-120

-110

-100

-90

-60

-50

-40

-20

+20

P215NL

1.0451

≤ 10

Longitudinal

–

P255QL

1.0452

≤ 25

Longitudinal

–

Transverse

–

>25 to ≤ 40

Longitudinal

–

Transverse

–

P265NL

1.0453

≤ 25

Longitudinal

–

Transverse

–

26CrMo4-2

1.7219

≤ 40

Longitudinal

–

Transverse

–

11 MnNi5-3

1.6212

≤ 40

Longitudinal

–

13 MnNi6-3

1.6217

Transverse

–

12Ni14

1.5637

≤ 25

Longitudinal

–

Transverse

–

> 25 to ≤ 40

Longitudinal

–

Transverse

–

X12Ni5

1.568

≤ 25

Longitudinal

–

Transverse

–

> 25 to ≤ 40

Longitudinal

–

Transverse

–

X10Ni9

1.5682

≤ 40

Longitudinal

Transverse

8.4 Appearance and internal soundness
8.4.1 Appearance
8.4.1.1 The tubes shall be free from external and internal surface defects that can be detected by visual examination.
8.4.1.2 The internal and external surface finish of the tubes shall be typical of the manufacturing process and the heat treatment employed. Normally the finish and surface condition shall be such that any surface imperfections or marks requiring dressing can be identified.
8.4.1.3 It shall be permissible to dress, only by grinding or machining, surface imperfections provided that after doing so, the wall thickness in the dressed area is not less than the specified minimum wall thickness. All dressed areas shall blend smoothly into the contour of the tube.
8.4.1.4 Any surface imperfection, which is demonstrated to be deeper than 5 % of the wall thickness T or 3 mm whichever is the smaller, shall be dressed.
This requirement does not apply to surface imperfection with a depth equal or less 0,3 mm.
8.4.1.5 Surface imperfections which encroach on the specified minimum wall thickness shall be considered defects and tubes containing these shall be deemed not to comply with this Part of EN 10216.
8.4.2 Internal soundness
8.4.2.1 Leak-tightness
The tubes shall pass a hydrostatic test (see 11.8.1) or electromagnetic test (see 11.8.2) for leak-tightness. Unless option 4 is specified. the choice of the test method is at the discretion of the manufacturer.
Option 4: The test method for verification of leak-tightness in accordance with 11.8.1 or 11.8.2 is specified by the purchaser.
8.4.2.2 Non-Destructive Testing
The tubes of test category 2 shall be subjected to a Non-Destructive Testing for the detection of longitudinal imperfections, in accordance with 11.11.1.
Option 5: The tubes of test category 2 shall be subjected to a Non-Destructive testing for the detection of transverse imperfections in accordance with 11.11.2.
Option 6: The tubes of test category 2 shall be subjected to a Non-Destructive testing for the detection of the laminar imperfections in accordance with 11.11.3.
8.5 Straightness
The deviation from straightness of any tube length L shall not exceed 0,0015 L. Deviations from straightness over any one metre length shall not exceed 3 mm.
8.6 Preparation of ends
Tubes shall be delivered with square cut ends. The ends shall be free from excessive burrs.
8.7 Dimensions, masses and tolerances
8.7.1 Diameter and wall thickness
Tubes shall be delivered by outside diameter D and wall thickness T.
Preferred outside diameters D and wall thicknesses T have been selected from ENV 10220 and are given in Table 6.
NOTE Dimensions which are different from those in Table 6 may be agreed.
8.7.2 Mass
For the mass per unit length the provisions of ENV 10220 apply.

Table 6 Preferred dimensions

dimensions in mm

Outside diameter D series a

Wall thicknesses Tmm

1,6

1,8

2,3

2,6

2,9

3,2

3,6

4,5

5,6

6,3

7,1

8,8

12,5

14,2

10,2

12,7

13,5

17,2

Bitmap

21,3

25,4

26,9

31,8

33,7

Bitmap

42,4

44,5

48,3

Bitmap

60,3

63,5

76,1

82,5

88,9

101,6

108

114,3

127

133

139,7

141,3

152,4

159

168,3

177,8

193,7

219,1

224,5

273

323,9

355,6

406,4

457

508

559

Category

Introduction.