We are based in New Delhi, India, with
excellent infrastructural facilities, which facilitate and fortify the
different activities and facets of our business. We have sophisticated
machines and technology to produce CR Coils, galvanized coil, ERW tubes,
steel galvanised coil, CRCA coils and sheets and galvanized products in
desired specifications and finishes.
The facilities include six 4 Hi-cold rolling mills and six bell type
annealing furnace. A list of other equipment include - Vickers Hardness
Tester, Rockwell Hardness Tester, Erichsen Testing Machine, Hydrostatics
Tester, Spectrometer, Metallurgical Microscope, Universal Testing Machine,
Roughness Tester and Bend Testing. The assemblage of sophisticated gadgetry
and systems are consistently kept under the vigilance of expert and
qualified technicians for regular checking of performance and quality.
The company understands the importance of innovation, which is the key to
our long term success and superior performance. We give prime importance to
research and development activities to keep up with the changing environment
and technology in steel pipes and tubes industry.
Typical ERW Pipe Manufacturing Process
Our manufacturing process generally involves the following stages in a step
by step procedure.
Slitting
HR Coils are slitted to pre-determined widths for each and every size of
pipes
Uncoiling, End Shearing And Welding
The slitted coil is uncoiled at the entry of ERW mill and the ends are
sheared and welded one after another. This results in a single endless
strip.
Forming
The slitted coils are initially formed into U shape and after that into a
cylindrical shape with open edges utilizing a series of forming rolls.
Welding
In this stage, the open edges are heated to the forging temperature through
high-frequency, low-voltage, high current and press welded by forge rolls
making perfect and strong but weld without filler materials.
Debeading
In this stage, the weld flash on top and inside (if required) is trimmed
out using the carbide tools.
Seam Annealing
If required, the welding portion and heat affected zone is put to
normalizing and then are cooled down in a air cooling bed.
Sizing
After water quenching, slight reduction is applied to pipes with sizing
rolls. This results in producing desired accurate outside diameter.
Cutting
In cutting stage, the pipes are cut to required lengths by flying cut off
disc/saw cutter.
End Facing And Bevelling
This is usually stage, where the pipes ends are faced and bevelled by the
end facer.
All these processes are continuous with automatic arrangements. These plain
ended tubes further go for processing as per the customer requirements such
as galvanizing, threading, black varnishing and more.
Manufacturing and Testing Flow Diagram of High Frequency Induction
Welded / Electric Resistance Welded Black and Galvanised Pipes / Tubes
The Manufacturing process utilizes the latest technology
and the most modern equipment for cold rolling, for producing high quality
cold rolled steel coils & sheets. The process includes judicious
selection of H.R. coils, that are sourced from best in country or from
imports and then providing them cold reductions which are suited to develop.
Desired mechanical properties & crystailographic orientation subsequent
to annealing & skin pass.
Pickling
In Fully continuous pickling line surface oxide layer of H.R. Coils are
removed by the action of warm hydrochloric acid , which is subsequently
rinsed by cold & hot water such that pickled H.R. coils does not carry
any acid & is neither under or over pickled.
Cold Rolling
The process consists of reducing thickness of hot rolled coils to desired
thickness in several passes (according to set pass schedule). This results
in :-
- Closer dimensional tolerance.
- Improved shape.
- Improved surface.
All mills are fitted with automatic gauge control to achieve uniform
thickness through out the width of the coil.
Annealing
Steel after undergoing cold rolling become very hard because of work
hardening & has got only limited use e.g. galvanizing because of loss of
ductility. In order to restore Ductility, Formability, C.R. coils are
annealed in protective Nitrogen - Hydrogen atmosphere such as to attain
desired grain size and orientation. This process results in improvement in
formability related properties & also in its microstructure.
Skin Passing
Skin passing of annealed cold rolled steel coils is carried out for
following: a) To suppress the yield point phenomenon which can cause
stretcher, strains on formed component. b) To remove the wrinkles &
achieve flatness that is caused due to annealing. c) To impart matte or
bright finish depending on customers requirements. In addition to this
semi-processed electrical steels are given about 7-8% critical reduction
such as to improvise their magnetic properties.
Slitting and shearing
After skin passing the coils are slit to the required width, by the
precision slitting machine. -The coils are further sheared to the desired
length facility. -The coils / sheets thus supplied to the exact sizes for
end users improve the yield of CR rolled steel and sheets.
Oiling & Packing
- The coils are provided with an uniform coating of special rust
preventive oil to guard against rusting, atmospheric corrosion & to
allow storage for long duration.
- The oil can be easily removed in normal degreasing.
- The coils/sheets are securely packed in bituminoid polyethylene lined
Hessian and tied with steel straps to avoid any damage in handling and
storage
Our Product Range