New Approach for Fabrication of Penstocks / Steel Liners for New Water Conductor System Khopoli by Modifying Joint Design

Abstract

High tensile quenched and tempered steel, ASTM A517 GrF or Sumiten 780S, is used for fabrication of penstocks of hydroelectric power plants. In the workshops, submerged arc welding process is used for longitudinal as well as for circumferential joints. When plate thickness is 12-22 mm, usual practice to have single V/double V edge preparation with suitable ischolar_main face of about 2mm with SMAW ischolar_main backing. Such joint preparation takes longer for completing welding. Hence joint design was modified having single V from one side and having ischolar_main face of about 6 mm with zero gap between the plates without SMAW backing. Such modification of the weld design would improve productivity substantially with saving of weld metal. Paper describes successfully implementation of modification of joint design and saving achieved IN terms of man-hours and cost of the deposited weld metals.