Spiral steel pipe is a kind of spiral seam steel pipe which is made of strip steel coil as raw material, often formed by warm extrusion and welded by automatic double-wire double-side submerged arc welding process. The spiral steel pipe will feed the strip steel into the welding pipe unit. After ro

1. It is strictly prohibited to disassemble and disassemble the expansion flange at the pipeline construction site; It is strictly prohibited to stretch, press, shorten and expand at random. 2. The pipe at both ends of the telescopic valve shall be concentric, and the two flange surfaces of the p

WELD Neck Flange is a kind of flange produced after forging blank. After forging blank, this kind of flange has high strength. The comprehensive degree can even be as good as that of special steel. In the production of flat-welded flanges, it is necessary to remove the iron on the surface of the we

Thin butt-welded flanges are often single-sided welding. In order to achieve penetration, the butt-welded flange should be left with a space of 1.4~1.6mm.　　Using thin welding wire (0.8~1.2mm in diameter) for short-circuit transfer welding, the welding current is 120~130A, and the arc voltage is 18~1

There are mainly the following six methods of pipe bending in the pipe bending factory　　 Stamping method: Use a tapered core on the punch to expand the pipe end to the required size and shape.　　Rolling wheel method: Put a core in the tube, and push the outer circumference with a roller for round edg

The difference between submerged arc welding and high frequency welding1. Submerged arc weldingSubmerged arc welding is a method in which the arc burns under the flux layer for welding. The welding arc burns between the welding wire and the weldment. The heat of the arc melts the base metal and flux

Large diameter welded steel pipe production processLarge diameter welded steel pipe production process mainly adopts cold forming process (JCOE), which is a gradual forming method of steel plate, so that the steel plate is formed into the required bending degree under the standard die of the upper p

Classification of thick-wall welded steel pipesThick-wall welded steel pipes include straight seam welded steel pipe SAWL, spiral welded steel pipe SAWH, high frequency welded steel pipe ERW, and combined welded steel pipe COW.Thick-wall welded steel pipes usually refer to steel pipes with a thickne

At the end of the pre-welded steel pipe (1) before milling, weld the pilot arc plate (2) to find a pilot arc plate with the same thickness as the base material. The distance between the roller and the cutter head should not be too narrow. Later, you will have to apply force laterally) (3) Method of

Special-shaped elbows are made by placing ordinary stainless steel decorative plates into grinding equipment to stop grinding. Grinding refers to a direct and useful processing method that uses mechanical, chemical, electrochemical and other principles to process metal surfaces to obtain a smooth an