Manufacturing Steel Tubes Division

Manufacturing

Acquired in

August 2006

Total Area

73,608 SQ. M

Capacity

39,600 MT/PA

Plants and Centres

Current capacity to manufacture 18000 MT of CDW tubes and 21600 MT of ERW tubes (Total– 39600 MT/PA) depending upon the sizes and mix.

Capability to manufacture Cylinder Bore tubes with ID Ra 0.5 max.

Produces Boiler Tubes with IBR (Self certification).

Captive power generation of 2100 KVA.

Facilities

We have a meticulously planned manufacturing set-up to serve as a ‘one-stop shop’ for a wide spectrum of tubing products.

Operated by a highly skilled and competent workforce to manufacture 3300MT Precision Carbon & Alloy Steel ERW and CDW tubes and tubes per month, our manufacturing division operates on the latest in tubing technology.

Backed by well-established processes and committed human resources, our integrated facility includes-

Coil Slitting – 1250mm and 400mm wide
Tube rolling – 15.88mm to 101.6mm OD up to 5.5mm thick
Tube annealing – 84 Tons per day
Tube drawing – 60 Kms /Day
Various tube finishing machines
Off line eddy current testing
Hydro-testing – up to 3000 PSi

Tube Mills

The tube mills installed have a series of forming rolls to anatomise the rolled strips in the tubular form followed by welding. The quick roll changeover not only minimises the production time but also contributes a lot to the overall capacity. The mills make use of variable high frequency induction welding technology offering the finest quality welding strength to the tubes with no material used as filler. The offline Eddy Current Tester further ensures the weld quality by inspecting the tube for any flaws.

The welded tubes are cooled to normal temperature by coolant sprays that pass through the sizing rolls, straightened and automatically cut off to the desired length by flying cutting machine. After this, all the tubes undergo end-finishing procedures like chamfering. Further, the facilities like, on-line edge preparation and external & internal bead removal in the mills ensure maximum tube strength and superior quality. The tubes are then tested, oiled, packed and dispatched.

Significant factors that contribute to the dimensional accuracy, durability, rust resistance, superior finish, and high strength of our ERW tubes include:

Exclusively designed rolls for progressive movement of steel strip
High frequency induction welding process
Deburring units for efficient removal of weld flash (both internal & external) for extra-smooth finish.
Turks head and sizing roll for straightening as well as perfect sizing of tubes into elliptical, oval, rectangular and square sections.
Eddy current testing, annealing, pressure testing, and cutting providing the tubes with fitness and quality required for the desired applications.

Specifications

Three Tube Mills with capacity – 40000 MT/ annum
Thickness from 0.90 mm to 5.5 mm
Up to 200 KW High Frequency Solid state Welders on all mills

CDW (Cold-Drawn Welded)

There are instances in tube manufacturing when the desired size might not be achieved directly from the mill. This is exactly where cold-drawing process comes into play providing the desired sizes.

The tubes in cold-drawing process undergo surface treatment to bring down the intensity of friction that takes place during the cold-drawing operations.

Manufacturing Process

It begins with annealing and surface treatment of ERW tubes
Cold swaging/push pointing procedures are applied for preparing pointed ends.
High precision close machined die is used for outer diameter control
Plug placed coaxial with outer die for inner diameter control
Annealing, straightening, and final testing are done to make sure the product is fit for the required application.

All Cold Drawn Welded (CDW) tubes produced feature excellent finish, durability, high precision dimensional tolerances, corrosion resistance, controlled and uniform mechanical properties and uniform sectional thickness.