DI PIPE MANUFACTURING PROCESS

Pre-analyzed liquid metal from Blast Furnace is taken in to Induction Furnace. The metal is superheated to a temperature of about 1520 o C and adjusted for chemical composition by addition of Steel Scrap and Ferro Silicon. The adjusted metal is taken into a converter for treatment to convert into SG iron. The adjusted from converter is transferred to Spinning Machines through ladles. The metal is poured to unlined water-cooled metallic moulds through a runner. The mould is kept at a slightly inclined position and rotated at high speed. The uniform flow of metal and uniform travel of the mould is ensured through flow control valves to achieve the uniformity in the thickness. Due to the centrifugal force the metal is held against the mould wall and the solidification of metal takes place due to water-cooling of mould. The pipe cast through above process known as DELVAD Process is heat-treated to achieve the requisite physical properties and microstructure. After heat treatment the pipes are coated externally with Zinc and then the pipes are finished before testing them with hydrostatic pressure. The tested pipes are lined internally with cement and then cured in the stream chamber. The lined pipes are ground and washed with water before sending them for bitumen painting. The pipes are preheated before bitumen coating on external surface. The coated pipes are sent to dispatch yard after marking.