Lock Hopper valve is a special metal to metal sealed ball valve designed for the complex working condition of coal gasification which could suit the condition of high pressure & temperature & needing high wear-resistance feature. Lock Hopper valve aims to solve the long existed problem of valve couldn’t close/open normally in pipeline of coal slurry feeding & black water process system due to the deposited medium & its wearing influence. So the lock hopper valve is a key valve in coal gasfication system to ensure system’s long life span.