Welded Pipes

Speaking about welded pipes, Instinox is one of the most well-known brand in India. We are known for our quickest deliveries and consistency in following ASTM Standards. Our firm has the largest inventory in the industry containing the highest stock in the country. Our goods are sold at properly competitive prices and known for its impeccable surface finish. Over the past 15 years, Instinox has a record of less than 1% rejection rate of the goods, above that we also provide product replacement warranty so that our customers get what they want with any ado. Instinox aims at winning customers hearts over monetary values. We provide after sales support and service to maintain customer relations. The Instinox buying experience is world class and this majorly helps keep our customers faithful towards our brand.

We at Instinox, discard problems that customers face when buying from other companies. Complaints about products quality or standards of materials are never faced by our firm. Many small firms face the problem of non-availability whereas Instinox never falls short of customers’ demands. We also excel at executing both small and bulk size orders. We provide same day shipping to our clients on urgent requests.

It is in general desirable that the properties of the weld are on equal level with those of the parent material. A correctly performed and clean weld can approach base material properties. Welding may cause innovation in the microstructure, corrosion resistance and affect the mechanical properties; hence, it is important to verify acceptable performance by satisfactory testing. The hardness, yield and tensile strength of the weld are mostly somewhat higher than for the base material while the impactful purposiveness and ductility often are lower. Residual stresses, which advances as the weld solidifies and cools, can be contracted significantly decline by solution annealing. The corrosion resistance of weld can be equal to the base metal for heat treated products (recrystallization and homogenization of the microstructure) or products welded with filler metals if flawless procedures are employed.

Welded tube is divided into electric-resistance welded tube, spiral tube as per the forming and welding method. ERW tube and butt welded tube are manufactured by continuous forming of a hot-rolled coil into a tubular shape by forming mills. Electric-Resistance-Welded (ERW) tube is produced by cold forming, and the seam welding is done by electric-resistance welding. This type of steel tube is used in large numbers as a lining tube for transporting petroleum and gas.

Side trimming and Edge milled steel strip or skelp are mechanically forced into the tube. There are two breaks down reels to make a round shape and feed the strip into crate forming stand. After passing three fin pass stand, a high-frequency electric current is passed to fuse or forge tubes skelp to form a weld. Unlike the arc welding technique no filler material is added. The weld then is a new homogeneous part of the completed tube. The welding facilities are assembled with the indicative system to control and show all information of operating such as cooling water circulations, power consumption, input & output voltage, and all the welded parameters.

In order to secure completely serene tubes, welds are trimmed both from inside and the outside. Immediate confirmation of welds is insured as the tube passes through a multi-probe ultrasonic inspection system which is located after the welding and trimming stages.

Following an ultrasonic assessment, to normalise the metallic structure of the weld, weld joints are consecration heated. Seam Normalizing called “N” process also improves firmness of the steel in the province and precisely declining the weld line corrosion effect.

After air cooling, the tube enters the water cooling stand and reduces the temperature of the weld seam. Prior to hydrostatic testing, tubes are sized to prescribed sizes before being cut to its required length and the ends are bevelled. Weld seams are again ultrasonically tested for not only weld seam but also for full lamination upon client needs.

Tubes are inspected, weighed and can be varnished and marked prior to final inspection and dispatch it to the coating plant to proceed with FBE and three layer coating for corrosion protection treatment.

Whenever necessary, tubes are threaded and coupled at the mill. Couplings are automatically made-up to a position with position/torque capacity. After coupling makeup, the tubes are transferred to an automatic drift station.

Continuous Welded Pipes, referring to small diameter products manufactured using continuous welding process, are primarily utilised for the supply of gas and water at low costs and higher productivity to maintain efficiency. Continuous Welded Pipes are treated the lowest cost variants among all steel tubes and find use informative applications, plumbing applications, and other low-pressure applications.

UO tube is manufactured by welding steel plate formed into a cylinder by a C press, a U press and an O press. The welding method used to manufacture UO tubes is hence known as seam welding. Needless to say, the seam weld metal mandatorily has to have the same mechanical properties as those required of the base metal. In developing a high-strength UO tube, it is absolutely necessary to design a weld metal which is compatible with the base metal. As a matter of fact, weld metal design is an indispensable element in the development of any new UO tube.

The spiral weld manufacturing process is one of the most cost effective ways to produce steel tube. The mill setup offers a varying degree of flexibility, allowing for a wide range of tube diameters and wall thicknesses to be produced. As a result, Skyline Steel is able to offer spiral weld products to many structural and non-structural markets at the most economical cost. Steel is continuously fed into the mill, edges are prepared and the tube is welded on the inside diameter (ID) and outside diameter (OD) thus generating full penetration welds.

Flash welding is a type of resistance welding that does not use any filler metals. The pieces of metal to be welded are set at a calculated distance based on material thickness, material composition, and desired properties of the finished weld. Current is passed on to the metal, and the gap between the two pieces creates resistance and produces the arc required to melt and mould the metal. Once the pieces of metal reach the proper temperature, they are pressed together, effectively forging them together.

To ensure high-quality products, Instinox has a third party certified quality assurance method, qualified welding systems and supervisors in charge who carry out visual inspection and qualified tests. The final tests are determined by the actual product standards and customer specifications.

At Instinox as a basis for the dimensioning of pressurised process piping systems in Europe is used for design and the tubing standard EN 10217-7 defines the technical dispatch conditions for standardised grades. Outside Europe, the ASME standards rules e.g. ASME B31.3 describes dimensioning rules on how to calculate internal design pressures for pipelines.