ERW pipe refers to a kind of high-frequency Electric Resistance Welding pipe. ERW pipe is divided into two forms AC welding and DC welding. ERW piping is an advanced-performance, leading quality, and cost-effective pipe for oil and gas storage and transportation, and it is ideal for most mechanical processing.
ERW Pipe Meaning
What is erw pipe? The erw material of erw pipe full form final product is between welded steel pipe and seamless material, and because of this, it is smoother and the surface texture is more consistent, so there are no obvious welds.
The surface of the ERW steel pipe is uncoated, the color is semi-smooth dark gray, and the weld is located inside.
Tuspipe has a state-of-the-art ERW pipe manufacturing process. TUSPIPE’s high-frequency welding is mainly used to produce thin-walled and normal-wall-thickness steel pipe.
ERW Pipe Dimensions- Electric Resistance Welded Tube
ERW steel pipe has the characteristics of using hot rolled coil as raw material, and the wall thickness can be controlled at ±0.2mm. The two ends of the steel pipe are repaired according to the American APl standard or GB/T9711.1 standard, and the delivery size is set.
Outer diameter: 21.3 mm to 660 mm
Thickness: 1.0 mm to 20 mm
Length: 3 m to 12 m, or customized length can be provided according to customer requirements
End: flat end, inclined end, thread.
Detailed data of erw steel pipe charts can be found by clicking here：ERW pipe
ERW Pipe Manufacturing Process
UNCOILING
The incoming coil is peeled and unrolled before being placed in a press roll. Flatten to remove coil groups to produce flat steel strips.
Uncoiler: plate width 200-1600mm, plate thickness 3-13mm, outer diameter: 2000mm, inner diameter: 750mm.
Accumulating
The ends of the coil are joined together by a butt weld to form a continuous strip.Slitting blades and milling edges trim strip edges to provide the precise strip width required during molding and ERW seam welding.
Clamping and leveling machine: width of steel plate: 200-1600mm, thickness of steel plate: 3-13mm
Forming
The forming process begins with the decomposition channel, where the material is gradually bent from a flat steel strip into a round tube to be submitted to the ERW seam welder.
Forming machine: diameterФ89-Ф426mm, thickness3.5-12.7mm
ERW High-frequency Welding
As the material passes through the welding mill frame, a high-frequency current flows into the strip edge through a conductive nozzle, generating the heat needed to bond the strip edge together.
Solid state high frequency welding machine：diameterФ89-Ф426mm，thickness3.5-12.7mm
Dual Heat Treatment
Heat treatment is an important part of pipe processing, pipe after high frequency welding, too fast or too slow cooling will bring damage to the performance of the pipe, heat treatment can keep the pipe performance in the best quality.
Linear induction heating device：diameterФ89-Ф426mm，thickness3.5-12.7mm
Sizing
The sizing section extrudes the welded pipe to the exact roundness, outside diameter and straightness tolerances specified by the customer.
Flat head chamfering machine: diameterФ89-Ф426mm, thickness3.5-12.7mm
Quality Control
After the welding is complete, quality control (QC) is carried out for visual inspection of the finished pipe, and if necessary, further ultrasonic (UT) testing is performed to ensure that the weld is free of defects.
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ERW Steel Pipe Mechanical Property
It is different from the welding process of ordinary welded pipes, and the weld is made of the base material of the steel strip body, and its mechanical strength is better than that of ordinary welding.
- Ultimate tensile strength: 132,000 psi 602 mpa. It is about 15% higher than ordinary welded pipe. erw steel pipe will melt the base material of the steel strip with high-frequency electric current to fuse the weld seam and the pipe body material completely. erw pipe has been subjected to a hydraulic burst test, and the maximum pressure it can withstand is not less than 20 MPa, equivalent to 200 atmospheres. The maximum pressure is not less than 20 MPa, equivalent to the strength of 200 atmospheres.
- Yield tensile strength: 74,185 psi 512 mpa. can maintain the shape without bending and deformation. ERW steel pipe has outstanding deformation resistance. Racks constructed with ERW steel pipe can support up to 3 tons in a single layer.
- Rockwell hardness: HRB75. 2-year life extension for harvester drive shafts made from ERW tubes.
- Brinell hardness: 90. ERW resistance-welded steel tubes have a stable overall structure. Packers with ERW steel frames have at least 40% less operating vibration.
Tuspipe produces ERW steel pipe that can be supplied with a material report for the steel grade that meets the standard, a weld flaw report, and a dimensional tolerance table for the allowable tolerance range of the high quality outer diameter (±0.5mm).
These unique properties can be easily customized to different shapes and sizes to meet customer needs in all directions.
In short, the resistance welding process has high production efficiency, relatively low manufacturing costs, and is suitable for large-scale production, saving materials and easy automation.
In addition, erw has the advantages of easy welding, cutting, forming, drilling and machining, which makes erw a very reliable and popular steel pipe in engineering.
