What Are the Differences Between SAW and ERW Pipe?
There are many kinds of pipes in the carbon steel pipe. You will see the weld steel pipe and seamless steel pipe. And in the welded steel pipe, you will find different methods of forming processes, such as erw, LSAW, SSAW.
So first, let’s see what the differences between saw pipes and erw pipe are.
In manufacturing processes, we can see SAW pipes (LSAW, SSAW) and ERW pipes are entirely different right from the formation and welding method, etc.
SAW Welded Steel Pipe Manufacturing Process:
In a single seam SAW steel pipe, the wedding is done with the help of the submerged arc welding process. In this method, a welding arc is submerged in welding flux. A Continues solid filler wire is fed from the outside. The pipe is welding two sides, first is inside, and then welding from the outside.
ERW Welded Steel Pipe Manufacturing Method:
When the ERW steel pipe welding process, two electrodes, usually made from copper, are used to apply pressure and current. The electrodes are disc-shaped and rotate as the material passes between them. This allows the electrodes to stay in constant contact with the material to make long continuous welds.
And hence, the performance of both the pipes different in the following aspects, you will see the details in five aspects following:
First, Let’s See it From Definition.
We see the differences between SAW pipe and ERW pipe from the definition firstly.
SAW pipe means Submerged Arc Welded pipe. And from different weld seam, there are two saw pipes, including LSAW and SSAW. As the name suggests, SSAW has a spiral weld seam. And LSAW has a longitudinal weld seam.
ERW pipe means Electric Resistance Welded pipe.
Second Differences Between SAW and ERW Pipe – We Will See It From The Weld Seam.
The surface quality is very important for pipes. Though both SAW and ERW pipes all have a weld seam. But for weld seam of ERW pipe is flat.
And the weld seam of the SAW pipe is not flat.
SAW pipe weld seam
You will see the weld seam of the LSAW pipe and SSAW pipe is higher than the steel plate. And the tolerance of weld seam height is specified in specifications.
If compare ERW pipes with SAW pipes, ERW pipes surface quality is better. ERW pipes are smooth and have a better finish. In most of the SAW pipes, it is mainly about the weld reinforcement internally and externally.
Third, the Defects Found in ERW Pipes Are Lesser Than SAW Pipes.
We will see it from the defects.
As there is a solvent deposit in SAW. It results in more defects apart from the defects in the volume. The defects found in ERW pipes are only confined to wire-line and straight welds and it can be inspected easily.
The defects can be noticed easily and the ultrasonic reflection on the surface makes it easier to detect. But for saw pipe, inspections are not only for weld seam but also for raw material. As the SAW pipes are all larger than 219 mm, and usually have thick wall thickness.
Forth Differences Between SAW and ERW Pipe – We Will See It From Residual Stress Ratio.
The residual stress ratio in ERW is lower than SAW pipes.
As ERW pipe deformation happens more in ERW followed by sizing of flat oval. It results in elliptical vertical changes and necking, thereby making the stress smaller.
The displacement of ERW pipes was smaller when compared along the axial and transverse incisions for comparison with SAW pipe built using the same material and it was also easy to detect.
Fifth Differences Between SAW and ERW Pipe – We Will See It From Overall Performance.
Although the overall performance of both ERW and SAW pipe are the same, once the pipes have a defect, the steel scrap and welding can be done on ERW, while it is not the same in case of SAW, which would result in cracking or corrosion, making the ERW more durable.
From these five aspects differences between SAW and ERW pipe, I think you already have some impression about SAW pipe and ERW pipe. Though we are professional LSAW pipe manufacturer, we learned about the ERW pipe and SAW pipes as well.
As to know the difference among them is convenient for us to introduce a suitable pipe for our customer’s projects. And if you have any questions, please contact me.
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