Press

Comparison of Characteristics Between ERW Steel Pipe and Spiral Submerged Arc Welded Steel Pipe


Both straight seam resistance welded steel pipes (ERW steel pipe) and spiral submerged arc welded steel pipes (SSAW steel pipe) can better meet the requirements of oil and gas pipelines. For medium-diameter (Ф630mm) steel pipes, ERW steel pipes are mostly used abroad. Spiral submerged arc welded pipes are generally only used for low-pressure fluid transmission, civil buildings, structures and piling pipes.

Due to the different forming, welding and process of ERW steel pipe and spiral submerged arc welded pipe in the pipe manufacturing process, there is a certain difference in performance between the two steel pipes.
(1) The surface quality of ERW steel pipe is better than that of spiral submerged arc welded pipe. The surface of ERW steel pipe is smooth, flat and beautiful. Spiral submerged arc welded pipe has high internal and external weld seams.
(2) The welding seam of ERW steel pipe is shorter than that of spiral submerged arc welded pipe. The welding seam of ERW steel pipe is as long as the length of steel pipe, and the welding seam of spiral submerged arc welded pipe is generally 1.4-1.7 times the length of steel pipe. The longer the weld, the higher the chance of welding defects.
(3) In the standard, the geometrical requirements for ERW steel pipes and spiral submerged arc welded pipes are basically the same, but in terms of physical objects, ERW steel pipes have sizing and straightening processes. Therefore, the geometric dimensions are higher than that of spiral submerged arc welded pipes.
(4) There are fewer types of weld defects in ERW steel pipes than in spiral submerged arc welded pipes. Spiral submerged arc welded pipes are welded by welding. There are many types of defects. In addition to volume defects, there are line subsidence. The ERW steel pipe weld has only line defects, and the weld is straight. It is easy to trace during the inspection process, and the defect is at the maximum reflection. Once there is a defect, the ultrasonic reflection is strong and easy to detect.
(5) The residual stress of ERW steel pipe is lower than that of spiral submerged arc welded pipe.
Because the ERW steel pipe is relatively deformed during the deformation process, and the subsequent sizing and ellipse sizing changes and shrinkage, the residual stress of the ERW steel pipe becomes smaller. Physical inspection shows that after the ERW steel pipe of the same specification and the same material is cut along the axis, the axial and lateral notch displacement is smaller than that of the spiral submerged arc welded pipe.
(6) The overall performance of ERW steel pipes is consistent. When defects occur in steel pipes, the steel pipes are discarded and repair welding is not allowed. Spiral submerged arc welding pipes allow repair welding, but the performance of repair welding is not consistent with the overall performance of steel pipes, and stress corrosion cracking is prone to occur at repair welding. Experiments have proved that the stress corrosion fatigue life of ERW steel pipes is longer than that of spiral submerged arc welded pipes.
(7) The quality of ERW steel pipe coating is higher than that of spiral submerged arc welded pipe.ERW production units have large investment, many processes, and relatively high processing costs for steel pipes. Because ERW steel pipes are not repaired, butted pipes are not allowed, and the relative yield is low. Therefore, the direct price of ERW steel pipe is about 300 yuan / T higher than that of spiral submerged arc welded steel pipe. From the overall cost analysis of pipeline construction, it does not increase. First, the quality of ERW steel pipes is good and the service life is long; second, the surface quality of ERW steel pipes is good, the coating is uniform, which saves a lot of coating materials, and the corrosion resistance of the steel pipes is low; High efficiency, in addition to reducing construction costs.

Reprinted from: www.gangguanjm.com



New service from OilVoice
Trip Shepherd is for companies who need to track their staff in areas of risk.
It's free to use, so we invite you to try it.

Visit source site

https://permanentsteel.com/

erw steel pipeSpiral Submerged Arc Welded Steel Pipessaw steel pipeCharacteristics

More items from lvy


Comparison of ERW Welded Pipe and Seamless Steel Pipe (tested by PetroChina Pipe Institute)

1. Outer diameter tolerance ERW steel pipe : It is cold-formed and sizing is completed by reducing the diameter by 0.6%. The process temperature is basically constant at room temperature. Therefore, the outer diameter is controlled accurately and the fluctuation range is small, which is helpful to ...

lvy lee - Permanent Steel Manufacturing Co.,Ltd


Posted 4 days agoPress > ERW Welded PipeSeamless steel pipePetroChina Pipe +1

Processing of High-strength Petroleum Casing Wire Tube Above N80Q Grade

The production method of high-strength petroleum casing (above N80Q grade) is generally completed by steelmaking, rolling, quenching and tempering, and pipe processing. During the production process, the outer diameter of the tube blank is controlled during the processing of the wire. The requiremen ...

lvy lee - Permanent Steel Manufacturing Co.,Ltd


Posted 5 days agoPress > Petroleum CasingN80 casing pipeWire processing

Testing Methods of Oil Casing Manufacturers

What are the detection methods of oil casing pipe ? Let's take a brief look: 1. Ultrasonic testing When ultrasonic waves are spread in the tested raw materials, the acoustic characteristics of the raw materials and the changes in the internal organization have a positive impact on the spread of t ...

lvy lee - Permanent Steel Manufacturing Co.,Ltd


Posted 10 days agoPress > oil casingTesting MethodsManufacturers

Comparison of Performance and Technical Indicators of ERW and SML

1. Tube blank quality ERW steel pipe  special steel has high purity. Through de-S, de-P, de-aeration, Ca treatment and other methods, the S and P content can be controlled below 0.005%, the N content can be controlled below 0.008%, the shape of the inclusions can be controlled to be spherical and t ...

lvy lee - Permanent Steel Manufacturing Co.,Ltd


Posted 13 days agoPress > ERWSMLSTechnical Indicators +1

Hardness Test Method for Seamless Steel Pipe

The hardness test of  seamless steel tube  can be divided into two methods, one is tensile test and the other is hardness test. The following small series is introduced in detail for everyone: The seamless steel pipe produced by the tensile test, the tensile tester of the sample will be pulled to t ...

lvy lee - Permanent Steel Manufacturing Co.,Ltd


Posted 19 days agoPress > Seamless steel pipeHardness Test
All posts from lvy