Stainless Steel Welded Pipe

Duplex Welded Stainless Steel Pipe is in the application of Petrochemical and Chemical industry, Onshore and Offshore Oil & Gas field of exploration, production and processing, Pulp and Paper-making industry, Ship Buliding industry, Coal industry and etc. Also used in producing all kinds of conventional weapons, the barrel, artillery shells and so on.  

Common Applications for Stainless Steel Tubing Stainless steel tubing has a number of uses in a wide variety of industries. It can be used during manufacturing in processing plants or can become part of a final product. Stainless steel tubing can also be used in pipelines to transport oil, gas, water, or chemicals.

The general features of our DSSP: superior corrision resistance, such as pitting corrosion, crevice corrosion, abrasion corrosion; better weldability and mechanical properties; excellent intergranular corrosion resistance and better cost- effectiveness.

Stainless steel can withstand corrosive or chemical environments due to its smooth surface.

Inspection & Quality Control:

Chemical Composition Analyzing                                         Flattening

Metallographic Test                                                              Flare & Flange

Mechanical Properties Test                                                  Reverse Bend

Hydraulic Test                                                                       Reverse Flattening

Non-destructive Test, including X-Ray Flaw Detection        Tensile Strength

Dimensional Checking                                                          Hardness

Welded Tube Standard Specifications

Welding Methods

Welded stainless steel tube is made from long strip or sheet, passed a rolling machine, then the strip edges is welded longitudinally and melt together, using various welding processes, making welding beam is as same as base metal, and form into tube shape.

The sheet width is desired tube outside diameter, the width should be calculated before manufacturing.

TIG

Tungsten Inert Gas welding, another name for Gas tungsten arc welding (GTAW), is an arc welding process that uses a non-consumable tungsten electrode to produce the weld. The weld area and electrode is protected from oxidation or other atmospheric contamination by an inert shielding gas.

EFW

Electric Fusion Welding, Electric Fusion Welding (EFW steel pipe) refers to an electron beam welding, the use of high-speed movement of the electron beam directed impact kinetic energy is converted to heat the workpiece so that the workpiece leaving the melt, the formation of the weld. It is mainly used for welding dissimilar steel welding sheet or which high power density, metal weldment can rapidly heated to high temperatures, which can melt any refractory metals and alloys. 

ERW

Electric Resistance Welding, high-frequency electrical current is passed between the material edges, then the edges are forced together under pressure as a butt joint and then welded by heating the material to high temperatures.

DSAW

Double Submerged arc welded, similar to other pipe manufacturing processes, the manufacture of Double Submerged Arc Welded Pipe involves first forming steel plates into cylindrical shapes. The edges of the rolled plate are formed so that V-shaped grooves are formed on the interior and exterior surfaces at the location of the seam. The pipe seam is then welded by a single pass of an arc welder on the interior and exterior surfaces.

LSAW

Longitudinal Submerge-arc Welded, LSAW (Longitudinally Submerged Arc Welded Steel pipes) in leaflets plate as raw material, the steel plate in the mold or molding machine pressure (volume) into using double-sided submerged arc welding and flaring from production.

HFW

High Frequency Welding, HFW welded steel pipes are widely preferred in Oil, Natural Gas, Water and other liquids transportation and distribution lines, heating, cooling, ventilation piping and steel structures for construction and other general purposes by means of precise production tolerances and high capacity manufacturing method.

Heat treatment is generally required after manufacture, this process improves stainless steel welded tube properties, help welded tube suitable for wide applications

Welded Tubes Quality Control

All stages from raw material to finished products, tube manufactured under strict quality control, making sure tube having stable mechanical properties, excellent surface finish and high dimensional accuracy.

   Standard Testing                                                        Optional Testing

   Tensile Strength test                                                   Ultrasonic test

   Flattening test                                                             Hydrostatic test

   Flare test                                                                     Air Under Water test

   Flange test                                                                  Grain Size  

   Dimensional inspection                                               Corrosion test

   PMI                                                                              Metallographic

   Hardness test                                                              Radiographic test.

   Eddy Current test