Blast Furnace Gas Butterfly Valve Replacement at a Southeast Asian Steel Plant
Project Overview
The project replaced large-diameter butterfly valves and gate valves on the blast furnace gas (BFG) system and hot blast lines of an integrated steel plant in Southeast Asia, solving gas cross-flow and high energy consumption caused by internal leakage.
Challenge
Blast furnace gas carries dust and sulfur and fluctuates widely in temperature. The original resilient-seated butterfly valves leaked badly after two years, causing gas cross-flow, unstable hot blast temperature and higher energy consumption. Replacement had to be completed within the blast furnace scheduled maintenance window with a tight schedule, and the large pipe sizes (above DN1000) and restricted site lifting space added difficulty.
Our Solution
Triple-offset metal-seated butterfly valves replaced the original resilient-seated valves (temperature and wear resistant, metal-to-metal sealing, hardfacing on sealing faces). Valves were pre-assembled to site pipe dimensions and pressure-tested individually, with sizes above DN1200 shipped in sections and assembled on site. Actuator and positioner interfaces were reserved for later automation upgrades.
Results
All replacements were completed within the maintenance window. After commissioning, gas internal leakage dropped significantly, hot blast temperature stability improved and energy consumption per ton of iron fell. The client is progressively replacing resilient-seated butterfly valves with triple-offset metal-seated solutions in later upgrades and continues to purchase spare parts.