This standard sets out the technical requirements for the delivery of welded stainless steel tubes with special requirements made of austenitic stainless steel (DIN 17457-1985).
1 Scope
This Standard applies to stainless steel tubes made of austenitic stainless steel, referred to as welded tubes, which may be used in the installation of systems for carrying out applications, including liquid (such as water, oil, etc.), gas, and pressurized steam, with special requirements in terms of safety, hygiene and quality, such as for food and beverage production, medical instruments, and offshore projects, and also for other applications requiring special requirements.
2 Designation — Specification
The tubes shall be designated according to DIN 17457-1985 and the customers requirements.
3 Dimensional and non-dimensional requirements
3.1 Dimensional requirements
3.1.1 The outside and inside diameters, wall thickness and length of welded tubes shall be within the specified ranges given in Table 1.
NOTE: Some special tolerances may be included in customers requirements.
3.1.2 The imperfections of the weld should also meet the requirements of Table 1.
Table 1 ranges and tolerances of different welded tubes
Outer diameter (mm)
Inner diameter (mm) Wall thickness (mm) Length (mm) Maximum imperfection (mm)
20–32 10–32 0.6–3.6 0–12 0.3
33–114 10–114 0.6–3.6 12–200 0.5
3.2 Non-dimensional requirements
3.2.1 The surface shall be smooth and clean, conforming to the requirements of Table 2 and the customers requirements.
Table 2 acceptance criteria for surface quality
No. Item Acceptance criteria
1 Surface Quality Visual examination
2 Surface finish No discernible burrs or signs of local metal displacement
3 No pitting or parting found in outside surface of tubes when examined under 10X Magnification
4 Any cutting or grinding residues shall be removed by buffing
4 Welding requirements
4.1 Welding materials and welding layer of tubes shall meet the requirements of Table 3 and Table 4.
Table 3 welding materials
No. Material
1 Austenitic stainless steel
Table 4 welding layer of tube
No. Material Thickness (mm)
1 Welding layer 0.3–0.7
4.2 The decrease of butt welds should not exceed 20% of the wall thickness.
5 Test methods
5.1 Non-destructive Test — Ultrasonic Examination
5.1.1 The welding layers shall be tested using ultrasonic examination with the acceptance criteria given in Table 5.
Table 5 ultrasonic acceptance criteria
Acceptance criterion
No indication of defects or cracks
5.2 Chemical composition
The results of the chemical composition analysis shall conform to the customer requirements or the standards specified in the customers requirements.
5.3 Mechanical properties
The mechanical properties test results shall conform to the customer requirements or the standards specified in the customers requirements.
6 Test reports and documentation
Test reports shall be drawn up according to the customers requirements. According to the customers requirements, the documentation required for the welding process shall be made available.
7 Packaging
The packaging requirements shall be in accordance with the customers requirements or DIN 17457-1985.
8 Marking and labeling
The marking and labeling shall be in accordance with the customers requirements or DIN 17457-1985.
9 Quality assurance
The quality assurance system shall meet the customers requirements or the standards specified in the customers requirements.
10 Quality control
The quality control system shall meet the customers requirements or the standards specified in the customers requirements.
11 Final inspection and acceptance
The final inspection and acceptance criteria shall meet the requirements of the customers requirements or the standards specified in the customers requirements.
