Execution standards

SR 6898-1 Spiral welded steel tubes for general purpose: installations, metallic constructions, etc.
Dimensions and linear weights See table 1.1
Steel OL 37.2, OL 42.2, OL 44.2, OL 52.2

STR 567 Spiral welded steel tubes for general purpose
Dimensions and linear weights According to STR 567
Steel Grd. B, X42, X46, X52

DIN 1615 Welded circular tubes of non-alloy steel, without special requirements
Dimensions and linear weights According to DIN 2458
Steel St 37.2, St 44.2, St 52.3

DIN EN 10219-1,2 Tubular profiles, welded, cold manufactured, for metallic constructions of non-alloy steels and of steels of fine granulation
Dimensions and linear weights According DIN 2458
Steel S 235 JRH

Note: On agreement between parties, other pipes can be manufactured in the dimensional range:
- diameter (219,1 - 1626) mm;
- wall thickness (4,8 - 12,5) mm;
as well as of other equivalent steel grades, too.

QUALITY TECHNICAL CONDITIONS ACCORDING TO SR 6898-1

1. Pipe category
MSH - guarantee of hydrostatic pressure resistance, mechanical characteristics of base material and welded seam, with welding quality factor min. 0,75
MH - guarantee of the hydrostatic pressure resistance, mechanical characteristics of base material, with welding quality factor min. 0,5

2. Dimensions and linear weights

Outside diameter
mm
Wall thickness , mm
4,80 5,20 5,60 6,40 7,10 7,90 8,70 9,50 10,30 11,10 11,90 12,50 14,20
Linear weight (Kg/ml)
219 25,37 27,43 29,48 33,57 37,12 41,14 - - - - - -
273 31,76 34,35 36,94 42,09 46,57 51,67 - - - - - - -
323 - 40,87 43,96 50,11 55,47 61,56 67,62 - - - - - -
355 - 44,93 48,33 55,11 61,02 67,74 74,42 - - - - - -
406 - 51,45 55,35 63,13 69,91 77,63 85,32 92,98 100,61 108,20 115,77 121,42 -
457 - - 62,34 71,12 78,77 87,49 96,18 104,84 113,46 122,05 130,62 137,02 -
508 - - 69,38 79,16 87,70 97,43 107,12 116,78 126,41 136,01 145,58 152,74 -
610 - - - 95,26 105,56 117,30 129,00 140,68 152,32 163,93 175,51 184,19 -
711 - - - 111,20 123,24 136,97 150,67 164,34 177,98 191,58 205,15 215,32 244,01
813 - - - - 141,10 156,84 172,56 188,24 203,88 219,50 235,09 246,76 279,73
914 - - - - 158,79 176,52 194,22 211,90 229,54 247,15 264,72 277,90 315,10
1016 - - - - - 196,39 216,11 235,79 255,45 275,07 294,66 309,34 350,82
1118 - - - - - - - 259,69 281,35 302,99 324,59 340,79 386,54
1219 - - - - - - - 283,35 307,01 330,63 354,23 371,92 421,91
1321 - - - - - - - 307,26 332.93 358,57 384,18 403,36 457,63
1422 - - - - - - - 330,91 358,57 386,20 413,80 434,50 493,00
1524 - - - - - - - 354,82 384,50 414,14 443,75 465,94 528,72
1626 - - - - - - - - 410,38 442,04 473,66 497,39 565,44

3. Tolerances

3.1 Outside diameter
MSH
MH
diameter <= 508 mm
+0,75%
-1,50%
+1,00%
-1,75%
diameter > 508 mm
+1,00%
-1,00%
+1,00%
-2,00%
3.2 Wall thickness
+15,00%
-12,50%
+15,00%
-12,50%

4. Lenghts

- random lenghts
6 - 12,5 m

5. Chemical requirements on liquid steel - %

Steel grade
C max.
Mn max.
P max.
S max.
Si max.
OL 37.2
0,18
0,80
0,050
0,050
0,40
OL 42.2
0,25
0,80
0,050
0,050
0,40
OL 44.2
0,20
1,10
0,050
0,050
0,50
OL 52.2
0,20
1,60
0,050
0,050
0,50

6. Mechanical requirements

6.1 Mechanical requirements of the base metal
Steel grade
Tensile strenght Rm, N/mm2, min.
Yield limit Rp 0,2, N/mm2, min.
Elongation %
min.
Impact testing at 20 Celsius degrees
KCU 300/2, J/mm2, min.
OL 37.2
360
240
25
69
OL 42.2
410
260
22
69
OL 44.2
430
280
22
59
OL 52.2
510
350
21
59

6.2 Mechanical requirements of seam - for MSH category

Steel grade
Tensile strenght, Rm, N/mm2, min.
Impact testing at 20 Celsius degrees, KCU 300/2, J/mm2, min.
OL 37.2
290
69
OL 42.2
310
69
OL 44.2
330
59
OL 52.2
390
59

7. Hydrostatic test pressure (bar)

- according to SR 1111, for each pipe of lot;
- the pipes must resist:

- 10 s at 40 bar for MSH
- 10 s at 25 bar for MH

8. Other quality checks

- non-destructive TVX checks along the lenght of welded seam up to 102 mm from the ends. The end zone and the repaired ones are XR and / or US checked;
- tensile testing of base material;
- bend testing of base material;
- impact bend testing of base material at 20 Celsius degrees;
- tensile testing of seam;
- bend testing of seam;
- impact bend testing of seam at 20 Celsius degrees;
- cold mandrel bend test at 180 degrees;
- checking of chemical analysis on pipe (at customer's choice).

DELIVERY, MARKING, PACKING, DOCUMENTS

- the pipes are delivered unprotected;
- the pipes are delivered with bevelled ends to an angle of 30 degrees +/- 5 degrees, keeping a front ring of 2 +/- 1 mm;
- each pipe will be marked - stencilled and painted at one of the ends;
- each lot of pipes will be accompanied by the mill test certificate according to EN 10204/DIN 50049;
- the delivery will be made by railway, truck or ship.

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