Material Selection Manufacturing routes Design criteria Coatings and Testing

1. Manufacturing Of
Large Diameter Pipes
For Oil And Gas
By:
•Faraz Shaukat
•Gohar Rehman
Sani
•Humble Khalid
Tareen

2.  Pipesfor water supply began to be used
around 2500 B.C.
 The Chinese transported water through
bamboo.
 The age of iron began about 1000 B.C.
 The Age of Steel was born in 1855 in
England

3. Steel has salient properties that can be utilized
to advantage in buried pipelines. The following
are desirable requirements of
buried, pressurized pipe.
These requirements can be achieved by welded
steel pipe:
• Strength
• Ease of installation
• High-flow capacity
• Leak resistance
• Long service life
• Reliability and versatility
• Economy

4.  Ingot production
 Producing blooms and
slabs
 Sheet Forming
 Shaping
 Welding
 Surface Operation

5. Molten steel is made by melting iron ore and coke
(a carbon-rich substance that results when coal is
heated in the absence of air) in a furnace, then
 removing most of the carbon by blasting oxygen
into the liquid. The molten steel is then poured
into large, thick-walled iron molds, where it cools
into ingots.
 In order to form flat products
such as plates and sheets, or long
products such as bars and
rods, ingots are shaped between
large rollers under enormous
pressure.

6.  To produce a bloom, the
ingot is passed through a
pair of grooved steel rollers
that are stacked. These
types of rollers are called
"two-high mills." In some
cases, three rollers are
used. The rollers are
mounted so that their
grooves coincide, and they
move in opposite directions.

7.  Blooms are converted into billets by putting
them through more rolling devices which make
them longer and more narrow.
 These billets are further converted into slabs
through same process of rolling.
 Slabs are also reworked. To make them
malleable, they are first heated to 1,204°C. This
causes an oxide coating to form on the surface
of the slab. This coating is broken off with a
scale breaker and high pressure water spray. The
slabs are then sent through a series of rollers on
a hot mill and made into thin narrow strips of
steel called sheets.

8. Seamless Welded
 Seamless tubes •Seamed tubes
are typically more are heavier and
light weight more rigid.
 used for bicycles
•used for things
and transporting such as gas
liquids transportation,
electrical conduit
and plumbing

9. Longitudinal Spiral
 Metal sheet is bend •Rollers bend
into tubular form sheet into
then welded in helical form
straight line. •Then welded
 Stress
into spiral shape
concentration at •Homogeneous
welded part stresses allover.
increases.

10.  Then rollers bend these
sheets into helical form.
 Inside, and later, outside
welding is performed by
an automatic submerged
arc process.
The molten weld and the arc zone are protected from
atmospheric contamination by being “submerged” under a
blanket of granular fusible flux consisting of lime, silica,
manganese oxide, calcium fluoride, and other compounds.

11.  Coating
 Hydrostatic testing
 Ultrasonic inspection
 Leakage

12.  Steel is used in manufacturing because it is
Economical,Leak Resistance,Easy to install,Long
service life and reliability.
 Seamless Pipes are not used because they are
light weight and large diameter seamless pipes
cannot be produced.
 Longitudinal welded Pipes are not used because
of stress concentration at one point,due to
which pipe fails early
 Spiral welded pipes are used because of uniform
stress allover.