BS EN 10305-3-2010 pdf download.Steel tubes for precision applications Technical delivery conditions Part 3: Welded cold sized tubes.
7 Manufacturing process
7.1 Steelmaking process
The steelmaking process is at the discretion of the manufacturer with the exception that the open hearth (Siemens-Martin) process shall not be employed unless in combination with a secondary steelmaking or ladle refining process.
Steels shall be fully killed.
NOTE This excludes the use of rimming, balanced or semi-killed steel,
7.2 Tube manufacture and delivery conditions
7.2.1 The tubes shall be manufactured from strip by electric welding. The tubes shall not contain strip end welds except for tubes to be supplied coiled for which the delivery conditions +A or +N may be specified.
Possible surface conditions are:
a) Si (black):
b) S2 (pickled);
c) S3 (cold rolled);
d) S4 (coated to an agreed condition).
NOTE The surface conditions Si and S3 apply for the strip. The surface condition S2 and S4 may apply for the strip or the tube: the purchaser should, where necessary. indicate the required condition at the time of enquiry and order.
7.2.2 Tubes made of the steel grades E155, E195, E235, E275 and E355 shall be supplied In the delivery condition +CR1 or +A or +N (see Table 1). Tubes made of the grades E190. E220, E260, E320, E370 and E420 shall be supplied in the delivery condition +CR2.
7.2.3 All non-destructive testing (NDT) activities shall be carried out by qualified and competent level 1. 2 and/or 3 personnel authorized 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 authorization issued by the employer shall be in accordance with a written procedure. NOT operations shall be authorized by a level 3 NDT individual approved by the employer.
8 Requirements
8.1 General
The tubes, when supplied in a aeiivery concntion inciicatea in I able 1 anci inspectea in accorciance with Clauses 9, 10 and 11. shall comply with the requirements of this document.
In addition, the general technical delivery requirements specified in EN 10021 apply.
8.2 Chemical composition
The cast analysis reported by the steel producer shall apply and comply with the requirements of Table 2. A steel grade not specified in this document may be specified (see option 1).
Option 1: A steel grade not specified in this document with a maximum total content of alloying elements of 5 % and agreed chemical composition, mechanical properties and delivery condition, is specified.
NOTE When subsequently welding tubes produced in accordance wrth this document, account should be taken of the fact that the behaviour of the stee’ during and after welding is dependent not only on the steel composition and the delivery condition, but also on the conditions of prepanng for and carrying out the welding.
Option 2: The composition of the specified steel grade shall be such that it is suitable for hot-dip galvanizing (see e.g. EN ISO 1461 for guidance).
Normally, the finish and surface condition shall be such that any surface imperfections requiring dressing can be identified. Any surface imperfections, which in accordance with the manufacturers experience might be considered defects as specified in 8.4.5. shall be dressed in accordance with 8.4.6, or the tube or part of tube shall be rejected.
8.4.2 The external weld bead shall be removed flush with the surface. The height of the internal weld is not limited, unless option 4 is specified.
Option 4: The height of the internal weld bead shall not exceed a specified value or be removed.
The wall thickness in the weld area shall not be lower than the specified minimum wall thickness.
8.4.3 Outside the weld area, the roughness on the outside surface shall be: Ru ≤ 4 pm.
8.4.4 Verification of surface roughness and/or improved levels of roughness may be specified (see options 5 and 6).
Option 5: The surface roughness shall be measured in accordance with 11.5 and reported.
Option 6: A specific surface roughness of agreed type and limiting value is specified. The roughness shall be measured and reported.
8.4.5 Surface imperfections which encroach on the specified minimum wall thickness shall be considered defects and tubes containing these shall be deemed not to conform to this document.
8.4.6 II 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.
8.4.7 Tubes in the delivery condition +A or +N shall be free of loose scale but may show discoloration.
8.4.8 Verification of internal soundness by non-destructive testing may be specified by the purchaser (see options 7 to 9).
Option 7: Non-destructive testing of the weld seam for the detection of longitudinal imperfections shall be carried out in accordance with 11.7.1 is specified.
Option 8: Non-destructive testing of the full tube circumference for the detection of longitudinal imperfections shall be carried out in accordance with 11.7.1 is specified.
Option 9: Non-destructive testing for verification of leak tightness shall be carried out in accordance with
11.7.2.
Strip end welds on tubes to be supplied coiled shall be subjected to an additional testing. The testing method is left to the discretion of the manufacturer, unless option 10 is specified.BS EN 10305-3-2010 pdf download.