Longitudinally welded threaded steel tubes - description
Longitudinally welded threaded tubes are made of hot-rolled strips. HF induction welding produces excellent homogeneous joint with a minimal heat affected zone. Furthermore, the tubes are subjected to continuous annealing furnaces with shielding atmosphere, straightening machines, milling cutters, chamfering units, pressurizing press and non-destructive testing. The parameters of welded tubes are manufactured to meet CSN, DIN, EN and GOST standards.
Specifications:
| Specifications | DIN 2440 | ISO light I | |||
| Comparable standards CSN EN | 10255 | ||||
| Black | Galvanized | Black | Galvanized | ||
| Comparable standards - CSN | 42 5710.0 | 42 5710.6 | 42 5712.0 | 42 5712.6 | |
| Comparable standards - DIN | 2440 | 2444 | |||
| Comparable standards - GOST | 3262 | ||||
| Inner diameter [", mm] | 3/8" - 4", DN 10 - 100 | 1/2" - 4", DN 15 - 100 | |||
| Outer diameter [mm] | 16,70 - 115,00 | 21,00 - 114,90 | |||
| Wall thickness [mm] | 2,35 - 4,50 | 2,35 - 4,05 | |||
| The delivery standards | CSN 42 0142 | ||||
Material quality:
Offer of steels by:
| ČSN | 11343, 11373 |
| DIN | USt34-2, USt37-2 |
| EN 10255 | |
| GOST |
Profile and size program:
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Surface finish:
The tubes are supplied in black oxidized or hot dip galvanized surface finish. Surface defects smaller than the tolerance limit of the wall thickness are allowed. Even though the external collar of the weld has been removed the seam may be still visible. The size of the inner collar depends on the wall thickness and meets standard. Following an agreement, the tubes (starting from the size of 6/4") can be supplied with the inner collar removed. Hot dip galvanized layer: min. 400 g/m2.
Heat treatment:
Upon requirement, the tubes can be delivered:
- without heat treatment (BK condition by DIN standard)
- normalized (NBK condition by DIN standard)
Lengths and tolerances:
| The range of lenghts | Lenghts [m] | Tolerances [mm] |
| Manufactured | 5 - 7 | |
| Approximate | 5 - 7 | ± 500 |
| Precise | 5 - 7 | + 100 |
Permissible tolerances of outer diameter, wall thickness and precision meet corresponding standards.
Packing and designation:
Tubes are supplied in band-blocked bundles in weight up to 2000 kg. Each bundle is fitted with the producer's label containing the data as follows:
- size
- steel grade
- lengths
- heat number
- weight in kg, by agreement length in m and number of pieces
- customer
In line with the customers agreement, the black threaded tubes are protected by a preservation agent against atmospheric corrosion during transport. The threaded tubes can be supplied:
- non-treaded with smooth ends
- treaded at both the ends
- treaded and with one sleeve
