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160
S
eptember
/O
ctober
2007
T
ube
M
ills:
R
olling &
F
orming
M
ethods
turn of the rollers. This way, the material
is deeply and perfectly worked during the
production process. It gives the final product
very unique, incomparable mechanical and
physical quality characteristics, suitable for
use in highly demanding conditions.
The products are mainly used for piping
systems (steam pipelines) for the
nuclear and classic power plants or heat
exchangers. These pipelines are resistant
to the chemical impact of the circulating
media. Power engineering often requires
low alloyed creep-resistant steels based on
molybdenum, or dispersive-strengthened
steels using vanadium carbide particles
(e.g. 16Mo3, 14MoV63). However, middle-
alloyed high-temperature steels – based on
chromium-molybdenum-vanadium-niobium
(eg P91, X10CrMoVNb91) – are more
commonly required for power plants.
The chemical industry requires tubes
based on chromium-molybdenum steels
(13CrMo45, 10CrMo910, 11CrMo910 and
25CrMo4), used in high pressures and
temperatures above 450°C. These grades
are also resistant to the hydrogen action,
with the field of hydrogen application
currently a major part of VVT’s R&D.
VVT tubes are also used in the area of oil,
gas and water exploitation and distribution.
The production of casing pipes includes
cutting of the threads on the ends of the
tube and on the inner surface of the
couplings for the thread protection. The
ends are beveled on pipelines produced
in accordance with API 5L for the trunk
distribution frame of the oil and natural
gas, as are the tubes produced in
accordance with EN10208-2 (linepipes for
combustible fluids).
VVT-Vitkovice Valcovna Trub as
– Czech Republic
Fax
: +420 595 956 140
Website
:
www.tube.cz›
VVT’s pipe is manufactured on 2 rolling mills: big and small Mannesmann pilger mills
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