Slide valve whitch can operate in erosive flow systems

摘要

A slide valve includes a housing providing an internal flow passage with which is associated a stationary valve member. A member with an orifice is movable between positions where the orifice is respectively aligned and non-aligned with the flow passage and a plate is secured to the stationary member to prevent the fluid channelling round it. Preferably the housing has a refractory liner within which a protective tube is embedded ; the tube may be metallic and welded to the plate. A purge gas may be introduced into the passage to clean the surfaces of the stationary and movable valve members ; it may be introduced both upstream and downstream of the members. In a modification the tube in the refractory liner is retained but the plate is not essential.