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Sections marked with a dot(●) contain details on agreements which shall, or may be, reached at the time of ordering.

1. Scope

This standard applies to seamless tubes 1) including tubes for headers of heat-resistant steels according to Table 1 which are used in the construction of boilers, pipe-lines, pressure vessels and equipment for service up to 600℃ and at simultaneous high pressures, where the tototal stress and the relevant scaling conditions can raise or lower the temperature limit.

5. Designation and ordering

5.1. The code numbers for the grades of steel were formed in accordance with Sections 2.1.1.1. and 2.1.2.2 of the Explanations to DIN Normenheft 3, and the material numbers according to DIN 17 007 Part 2.

5.2. The code number or the material number for the steel grade shall be appended to the symbol for the product according to the following examples :

Example 1:

Designation of a seamless steel tubes of 38mm outside diameter and 2.6mm wall thickness according to DIN 2448 of steel St 35.8, material number 1.0385 :

Tabe DIN 2448 - sT 35.8 x 2.6

or Tabe DIN 2448 - 1.0305 - 38 x 2.6

5.3. The order shall not only specify the designation according to Section 5.2 but also in every case the desired total length and the desired acceptance inspection certificate and for unalloyed steel tubes also the steel grade. In addition, further details in compliance with the other Sections marked with a dot(●) can be agreed at the time of ordering.

DIN 8528 Part 1 Weldability; metallic materials, definitions

Table1. Summary of heat-resisting steels for seamless tubes, their chamicalcomposition (cast analysis) and colour designation of tubes

Table 2. Permissible deviations in the chemical composition of the sample analysis from the limits quoted in the cast analysis (see Table 1)

Table 3. Scope of tests for seamless tubes in both quality grades and authority for the execution of the testings.

Table 4. Limits governing the application of quality grades I and III