|

Execution
standards
| STAS
7656 |
Longitudinally welded steel
tubes for water, gas and steam installation |
| Dimensions
and linear weights |
According to STAS 7656,
see table 4.1 |
| Steel |
OL 32, OL 34, OL 37 |
| DIN
1626 |
Welded circular tubes of
non-alloy steel with special quality requirements |
| Dimensions
and linear weights |
According to DIN 2458 |
| Steel |
St 37.0 |
| DIN
2440 |
Medium weight steel tubes
suitable for threading |
| Dimensions
and linear weights |
According to DIN 2458 |
| Steel |
St 37.2 |
| DIN
2441 |
Heavy weight steel tubes
suitable for threading |
| Dimensions
and linear weights |
Conform DIN 2458 |
| Steel |
St 37.2 |
| ISO
65 |
Carbon steel tubes suitable
for threading according to ISO 7/1 |
| Dimensions
and linear weights |
According to ISO 65 |
| Steel |
TW.0 |
| BS
1387/85 |
Steel tubes and tubular
profiles with threads and couplings and with plain edns, suitable
for welding and screwing |
| Dimensions
and linear weights |
According to BS 1387/85 |
| Steel |
Non-alloy steel for general
purpose with the tensile strenght between 320 si 460 N/mm2 |
| GOST
10704 |
Electrically welded steel
line - weld tubes |
| Dimensions
and linear weights |
According to GOST 10704 |
| Steel |
St 1, St 2, St 3, 10 |
| GOST
10705 |
Electrically welded steel
line - weld tubes |
| Dimensions
and linear weights |
According to GOST 10705 |
| Steel |
St 1, St 2, St 3, 10 |
| DIN
2444 |
Hot dipping galvanized
tubes |
| UNI
5745 |
Hot dipping galvanized
tubes |
| ASTM
A 53 |
Hot dipping galvanized
tubes |
Note: By agreement between parties,
tubes of other typified steel grades can be manufactured, with
the maximum tensile strenght of 490 N/mm2.
QUALITY
TECHNICAL CONDITIONS ACCORDING TO STAS
7656
| 1. Pipe
category |
| M medium series |
| G heavy series |
| U light series |
2.
Dimensions
and linear weights according
to STAS 7656 (Tabel 4.1)
|
Nominal
diameter
|
Outside
diameter
|
Light
series
|
|
mm
|
Symbol
|
Calculation
(mm)
|
max.
(mm)
|
min.
(mm)
|
Wall
thickness (mm)
|
Linear
weight (kg/ml)
|
|
Black
tube
|
Galvanized
tube
|
|
15
|
1/2
|
21,3
|
21,7
|
21,0
|
2,3
|
1,08
|
1,15
|
|
20
|
3/4
|
26,9
|
27,1
|
26,4
|
2,3
|
1,39
|
1,49
|
|
25
|
1
|
33,7
|
34,0
|
33,2
|
2,9
|
2,20
|
2,32
|
|
32
|
1
1/4
|
42,4
|
42,7
|
41,9
|
2,9
|
2,82
|
2,97
|
|
40
|
1
1/2
|
48,3
|
48,6
|
47,8
|
2,9
|
3,24
|
3,42
|
|
50
|
2
|
60,3
|
60,7
|
59,6
|
3,2
|
4,49
|
4,72
|
|
65
|
2
1/2
|
76,1
|
76,3
|
75,2
|
3,2
|
5,73
|
6,02
|
|
80
|
3
|
88,9
|
89,4
|
87,9
|
3,6
|
7,55
|
7,89
|
|
100
|
4
|
114,3
|
114,9
|
113,0
|
4,0
|
10,8
|
11,30
|
|
Nominal
diameter
|
Outside
diameter
|
Medium
series
|
|
mm
|
Symbol
|
Calculation
(mm)
|
max.
(mm)
|
min.
(mm)
|
Wall
thickness (mm)
|
Linear
weight (kg/ml)
|
|
Black
tube
|
Galvanized
tube
|
|
15
|
1/2
|
21,3
|
21,8
|
21,0
|
2,6
|
1,21
|
1,27
|
|
20
|
3/4
|
26,9
|
27,3
|
26,5
|
2,6
|
1,56
|
1,65
|
|
25
|
1
|
33,7
|
34,2
|
33,3
|
3,2
|
2,41
|
2,53
|
|
32
|
1
1/4
|
42,4
|
42,9
|
42,0
|
3,2
|
3,10
|
3,24
|
|
40
|
1
1/2
|
48,3
|
48,8
|
47,9
|
3,2
|
3,56
|
3,73
|
|
50
|
2
|
60,3
|
60,8
|
59,7
|
3,6
|
5,03
|
5,24
|
|
65
|
2
1/2
|
76,1
|
76,6
|
75,3
|
3,6
|
6,42
|
6,71
|
|
80
|
3
|
88,9
|
89,5
|
88,0
|
4,0
|
8,36
|
8,70
|
|
100
|
4
|
114,3
|
115,0
|
113,1
|
4,5
|
12,2
|
12,60
|
|
Nominal
diameter
|
Outside
diameter
|
Heavy
series
|
|
mm
|
Symbol
|
Calculation
(mm)
|
max.
(mm)
|
min.
(mm)
|
Wall
thickness (mm)
|
Linear
weight (kg/ml)
|
|
Black
tube
|
Galvanized
tube
|
|
15
|
1/2
|
21,3
|
21,8
|
21,0
|
3,2
|
1,44
|
1,50
|
|
20
|
3/4
|
26,9
|
27,3
|
26,5
|
3,2
|
1,87
|
1,96
|
|
25
|
1
|
33,7
|
34,2
|
33,3
|
4,0
|
2,93
|
3,05
|
|
32
|
1
1/4
|
42,4
|
42,9
|
42,0
|
4,0
|
3,79
|
3,94
|
|
40
|
1
1/2
|
48,3
|
48,8
|
47,9
|
4,0
|
4,37
|
4,54
|
|
50
|
2
|
60,3
|
60,8
|
59,7
|
4,5
|
6,19
|
6,40
|
|
65
|
2
1/2
|
76,1
|
76,6
|
75,3
|
4,5
|
7,93
|
8,22
|
|
80
|
3
|
88,9
|
89,5
|
88,0
|
---
|
---
|
---
|
|
100
|
4
|
114,3
|
115,0
|
113,1
|
---
|
---
|
---
|
3.
Tolerances
| 3.1 Permissible
variantions in outside diameter |
According
to table 4.1 |
| 3.2 Permissible
variantions in wall thickness |
+/-
12,5%
|
In isolated
places and on lenghts not exceeding twice the outside diameter
deviations of - 15% are allowed.
|
| 3.3
Permissible variantions in weight |
on each pipe
+/- 10% |
| per waggonable
lot of min. 10mt weight +/- 7,5% |
4. Lenghts
| - random
lenghts |
4
- 6 m
|
| -
fixed lenghts within the manufacture lenghts of 6000 +/- 100
mm |
5.
Chemical
requirements - %
| Steel
grade |
Quality
class |
Composition,
%, max. |
Disoxidation
degree |
|
C
|
Mn
|
P
|
S
|
|
OL
32
|
1,
1a, 1b
|
0,15
|
0,60
|
0,055
|
0,055
|
---
|
|
OL
34
|
1,
1a, 1b
|
0,17
|
0,60
|
0,055
|
0,055
|
---
|
|
OL
37
|
1,
1a, 1b
|
0,25
|
0,85
|
0,065
|
0,065
|
---
|
|
2
|
0,22
|
0,85
|
0,055
|
0,055
|
---
|
6.
Mechanical
requirements
|
Steel
grade
|
Quality
class
|
Yield
limit Rp 0,2, N/mm2, (Kgf/mm2)
|
Tensile
strenght Rm, N/mm2, min. (kgf/mm2)
|
Elongation,
min %
|
|
OL
32
|
1,
1a, 1b
|
180
(18)
|
310...390
(32...40)
|
33
|
|
OL
34
|
1,
1a, 1b
|
210
(21)
|
330...410
(34...42)
|
31
|
|
OL
37
|
1,
1a, 1b
|
240
(24)
|
360...440
(37...45)
|
25
|
|
2
|
240
(24)
|
360...440
(37...45)
|
25
|
7.
Hydrostatic
test pressure
(bar)
- max 50
bar or eddy currents check according to SEP 1925
8.
Other
quality checks
-
bend testing (at customer's choice);
- flattening test (at customer's choice);
- electromagnetic testing;
- checking of chemical analysis on pipe (at customer's choice).
DELIVERY,
MARKING, PACKING, DOCUMENTS
-
the pipes are delivered unprotected or hot-dipping galvanized;
- the pipes are delivered with bevelled unthread ends and not
internally debbured, in bundles with fixed number of pieces,
packed in hexagonal shape, tied in minimum five places with
steel strips;
- a tag will be attached to each bundle;
- 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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