Seamless tubes for pressure equipment made from fine-grained steels

Tubes for pressure and thermal equipment made from fine-grained steels with a ferritic grain size of 6 and finer are used in areas where it is necessary to guarantee the required parameters of the notched impact strength of the steel. The tubes are used for parts of energy equipment such as boilers, steam superheaters, steam pipelines, etc.

We offer a wide range of solutions within the following parameters:

Tube dimensions and tolerances for pressure equipment

OUTER DIAMETER (OD)10.2 - 139.7 mm
(from 26.9 mm manufactured as hot rolled)
WALL THICKNESS (WT)0.5 - 16.0 mm
(from 2.6 mm manufactured as hot rolled)
Tubes are delivered according to
EN 10216-3,
(DIN 2448)
tube sizes acc. to European standards
.

GOST and TU

tube sizes acc. to Russian standards
EN 10 305-1
(DIN 2391-1)

tube sizes for precision steel tubes.

Means of tube production – hot rolling or cold forming depends upon the standards, tube dimensions and the agreement when ordering the tubes. The tube tolerances meet the appropriate standards and requirements.


Steel for tubes made from fine-grained steel

EN 10216-1 P355N, P460N, P355NH, P460NH, P275NL1, P355NL1, P460NL1, P275NL2, P355NL2, P460NL2
Marking system for steel grades according to EN
Chemical composition and mechanical properties of steels acc. EN 10216-1 a DIN 17179

Steel comparison according to DIN and EN standards. The fine-grained steels are supplied in 4 types of qualities
DIN 17179
EN 10216 - 3
marking
steel grades
marking
steel grades
Basic
StE
255, 285, 355,
420, 460
P-N
355, 460
High - temperature
WstE
255, 285, 355,
420, 460
P-NH
355, 460
Low - temperature
TstE
255, 285, 355,
420, 460
P-NL1
275, 355, 460
Low - temperature custom
EStE
255, 285, 355,
420, 460
P-NL2
275, 355, 460
Comment: steel in the Q state – treated is not shown in the overview.


Length of seamless boiler tubes

Length [m]for sizes [mm]
5 – 6 OD < 60.3
5 – 6 or 10 – 14OD => 60.3 and WT < 7.1
5 – 6 OD => 60.3 and WT => 7.1
Longer tubes (22 - 24 meters) can be supplied upon agreement
Types of supplied length of tubes are:(a) random length,
(b) fixed length ± 500 mm,
(c) exact length
L < 6 m 0 + 10 mm
L = 6 - 12 m 0 + 15 mm.
L > 12 m + upon agreement
 

 


Tube ends

The ends are vertical to the longitudinal
axis and are without burrs.

The tubes with deburred ends
or ends customized for welding.

Deburring applies to
Tube OD26.7 - 114.3 mm
    Tube ends
Tube WT 3.2 - 12.5 mm
Tube lengths4 - 13 meters
Deburring angle, a30°+ 5 and 37°± 2.5
Dimension, c1.6 ± 0.8 mm

Markings of the tubes and tube bundles

(a) The tubes with outside diameter up to 51 mm may be marked by a label attached to the tube bundle,
(b) Larger tubes must, at least, have markings at one end of the tube with the necessary data - producer name, standard, steel grade, test category, heat no, inspector's mark, identification number. Additional marking upon agreement.

Packaging of seamless boiler tubes

The tubes are supplied in packages with a circular or hexagonal outline with having weight of 300 – 3 500 kg.


Testing of the tubes made from fine-grained steel

The tubes may be tested according to the test category 1 (without ultrasound) or according to the test category 2 (with ultrasound).

Straightness of tubes

Allowed straightness is 0.15 % of the total tube length, for 1 meter length the allowed straightness is 3 millimeters.

Surface protection of the tubes

While ordering, it is necessary to agree upon the method and means of temporarily protecting the surface of the tubes during transportation and storage. The tubes may be supplied without temporarily preservation of the surface or with an agreed upon preservative.
Related links