Electric resistance welded pipe

The three manganese levels are typical of, respectively. Electric Resistance Welded pipe (ERW) at 1% 0.0 pipe at (a newly developed forming technique for the manufacture of very large pipe out of heavy plate sljieel) and the new I -Mo-Cb steels developed mainly in the U.S. by Amax (Ui). Because of the limited solubility of calcium in steel, the only way these ratios can be achieved, particularly in high steels and for the most critical property levels, is by extreme desulfurization down to 0,00h% max, in the easiest case and 0.001% max. in the most unfavorable situation. 

Electric resistance weld pipe manufacturing process.114... 

Electric resistance weld pipe is made from strip in coil form. After being uncoiled, flat strip is progressively rounded as it passes through a series of vertical and horizontal forming rolls before welding. Small-diameter pipe is welded by the high frequency induction method and medium-diameter... 

Pipe-Making. In many respects the tube-making methods used in Europe are the same as those used in the United States. There are some differences. Flash-butt welding of line pipe is unknown in Europe. More importantly electric resistance welded pipe, which can be obtained in quite large diameters in the United States, is sometimes available only in small diameter tube in Europe. If large size ERW pipe is ordered in Europe, fusion welded pipe may be delivered Fusion welded pipe may or may not be an acceptable alternative. 

Examples of SOHIC failure in spiral-welded line pipe are common forms of failures. Failures were also encountered in electric-resistant welded pipes because of HIC. Failures of seamless line pipes have also been reported (30). HIC-related damage and failures of 20 line pipes in H2S and CO2 atmospheres have been reported (19). Despite the availability of adequately HIC-resistant line pipe since the late 1970s, failures are still occurring in pipelines constructed since then. 

Three-layer polyolefin Excellent combination of properties Best suited for electrical resistance welded pipes High thickness to eliminate weld tenting... 

A Russian ammonia pipeline of nearly 2400 km extends from Togliatti on the Volga River to the Port of Odessa on the Black Sea, and a 2200-km, 250-mm dia branch line extends from Godovka in the Ukraine to Panioutino. The pipeline is constmcted of electric-resistance welded steel pipe with 7.9-mm thick walls but uses seamless pipe with 12.7-mm thick walls for river crossings. The pipeline is primed and taped with two layers of polyethylene tape and suppHed with a cathodic protection system for the entire pipeline. Mainline operating pressure is 8.15 MPa (1182 psi) and branch-line operating pressure is 9.7 MPa (1406 psi) (11). 

Recently, attention has been directed to a study of the problem of grooving corrosion in line-pipe steel welded by high frequency induction or electric resistance welding. In sea water, it seems to be related to high sulphur content in the weld zone, the type of environment, its temperature and velocity The importance of sulphur is significant since Drodten and... 

A 135 Electric-Resistance-Welded Steel Pipe [Note (2)]... 

Figure 15. Off-shore platform node construction showing the complex welding assembly job requiring outstanding resistance to lamellar tearing in the electric-resistance-welded (ERW) steel pipe stock. Excellent through-thickness ductility is obtained by low sulfur plus REM treatment in the ladle, plunging a mischmetal...

The most important form of corrosion in fresh waters is localized corrosion of steel and it is critical in water pipes because it might result in leaks in pipes. The major types of localized corrosion of steel in fresh water are pitting under tubercles groove corrosion of electric-resistance welded (ERW) pipes and pitting at discontinuities in corrosion product films. 

For instance, for a 304 stainless steel welded seam pipe with an outside diameter of 3V2", to find the maximum internal pressure allowed for this pipe, use the pressure formula. Find what is called the stress value for a particular material (in this case 304 stainless steel) which is based on that material and the way it was fabricated - whether it is seamless, continuous welded, electric resistance welded, or electric fusion-arc welded. Most of the materials that you will run into will be ERW (electric resistance welded ) and thus have a seam, or will be seamless with no weld. The same material of a given diameter and thickness will be able to withstand higher internal pressure if it is seamless. 

For general purpose calculations I assign a stress value (S) of 18800 psi to 304 and 316 stainless steel piping and tubing that is seamless, and a stress value of 16000 to the above with an ERW (electric resistance weld, in other words, with a seam). Please note that appropriate values need to be found in manufacturer s publications or in the reference materials noted above. 

ERW-Pipe. If run-of-the-mill pipe inconsistencies disturb you, and they should, inquire about ERW (electrical resistance welded) carbon steel pipe. This has more consistent properties than the usual steel pipe. You should be able to buy ERW-pipe for essentially the same price as pipe meeting your old specifications. 

Poor workmanship and defective materials can increase corrosion. Water turbulence effects can be increased by poor workmanship, such as the failure to ream burrs from cut ends of copper pipe. This increases the turbulence at the joints and results in erosion of the copper. Excessive and corrosive flux used in soldered coppers joints results in pitting corrosion along the flux runs. Incomplete longitudinal welds in electric resistance welded (ERW) steel pipe result in concentration cell corrosion and rapid corrosion. 

The pipeline was manufactured from carbon steel schedule 40 electrical-resistance-welded seamed pipe. This is virtually the industry-standard for a large proportion of pneumatic conveying pipelines. 50mm nominal bore was used as previous experience indicated this to be the smallest size from which scaling-up to substantially larger sizes gave acceptable accuracy. 

Electric-welded pipe is defined as pipe having one longitudinal seam formed hy electric-flash welding or electric-resistance welding, without the addition of extraneous metal. The weld seam of electric-welded pipe should he heat treated after welding to a minimum temperature of 538 °C (1000 °F), or processed in such a manner that no untempered martensite remains. 

The resistance overpotential of the cell IR is mainly a function of the conductivity of the electrolyte solution and the distance between the electrodes as the electrolytic resistance is more important than the electric resistance of the metals. Thus if dissimilar pipes are butt-welded with the flow of electrolyte, the most severe corrosion will occur near the weld on the active metal. In soft water, the critical distance between... 

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