DONGSHANG Stainless produce welded stainless steel tube for pressure purposes, manufacturing and design comply to part 7 of EN 10217 standard, welded tubes made of Austenitic or austenitic-ferritic stainless steel applied for many industries, not only under room temperature condition, and low as well as elevated temperature environment.
|Tube type||welded tube|
|Grades||1.4301, 1.4307, 1.4404, 1.4541, 1.4571, 1.4462|
|Finishing||as welded, annealing pickling, bright Annealing, polished|
|Outside diameter||6 up to 508 mm|
|Thickness||0.5 up to 8 mm|
The tubes will be manufactured from hot or cold rolled plate, sheet or strip 1D, 2D, 2E, 2B surface, by longitudinally arc or laser welding. DONGSHANG stainless offer descaled, heat treated, bright annealing condition welded tubes, like symbol W2(b), W2A(b), W2R(b).
We use automatic TIG welding type to weld tubes, and remove inside seam and external seam, making inner and outer surface more smooth and perfect roughness.
EN 10217-7 common steel grades and equivalent AISI grades
|Steel name||Steel number||AISI grade|
When tube is finished, chemical composition analysis should be carried out according to EN 10217-7, to ensure the correct grade by direct-reading spectrometer or PMI tester.
The tolerance on outside diameter and wall thickness of tubes should be limited according to EN ISO 1127, precise tolerance should be minimized as much as possible, which has a perfect performance for many applications.
Tolerances on outside diameter and wall thickness of tubes
|Outside diameter D mm||Tolerance on outside diameter D||Tolerance on wall thickness T|
|Tolerance class||Permissible deviation||Tolerance class||Permissible deviation|
|D ≤ 168,3||D3||± 0,75 % or ± 0,3 mm whichever is the greater||T3||± 10 % or ± 0,2 mm whichever is the greater|
|D4a||± 0,5 % or ± 0,1 mm whichever is the greater|
|D >168,3||D2||± 1,0 %|
Testing and inspection on EN 10217-7 welded tube
All the inspection and testing finished on welded tubes, 3.1 type Mill Test Certificate should be provided according to EN 10204, quality control department guarantee tubes high quality and good performance in various applications.
- Tensile test
- Flattening test
- Leak tightness test
- Dimensional inspection
- Visual examination
- Eddy current
- Ultrasonic test
- Radiographic test