Pressure-reducing valve for coal liquefaction and coal gasification plants

摘要

In a pressure-reducing valve, erosion and corrosion, which are caused by suspension-like fluids containing insoluble solid materials in coal liquefaction and gasification processes, are prevented. Parts of the pressure-reducing valve, which can be damaged by erosion and corrosion due to the suspension-like fluids, are covered or coated with superhard materials which comprise intrusion-type compounds of transition metals of groups IVa, Va and VIa of the periodic table of the elements, or of silicon carbide, boron or boron compounds or the like.