Welded steel pipes are tubular products made from flat plates, called skeletons, which are formed, bent and prepared for welding. The production process of welded steel pipe is simple, with high production efficiency , large variety of specifications and the less equipment .With the rapid developmen

At all stages of the heat treatment process, the temperature must be accurately monitored and recorded by a thermocouple or other suitable, approved method, to guarantee that the temperatures specified in the WPS are adhered to during the welding process. When necessary these temperatures must be re

Steel pipe should be welded, except for joints which need to be taken apart for service, which will be flanged. It is essential that welding is carried out by competent craftsmen and is subject to stringent inspection.Flanges for ammonia (and preferably, also, for other refrigerants) must be of the

Hot dipped galv.seamless steel pipe is a steel pipe coated with a layer of zinc on the surface. The molten metal reacts with the substrate to form an alloy layer, so that the coating and the substrate are firmly bonded, and the thickness of the coating is uniform. It also has good corrosion resistance due to its galvanized coating.

Steel pipesSteel pipes to BS 1387 are normally specified in the nominal bore sizes given in Table 1. Finishes can be black or galvanised, the latter being preferred for corrosion resistance.

MECHANICAL PROPERTIES OF WELDED JOINTSteel pipes used are API 5LX X52 and X60, with 16 inch outer dia. The wall thickness is 0.5 inch for X52 and 0.25 inch for X60. Welding wire used is of 1.2 mm dia., containing REM. Chemical compositions of pipes and the filler wire are listed in attached Table.