Valves and pipes for corrosive liquids in chemical plant - using expensive metal liners inside inexpensive supporting shells

An inner lining is made of expensive material (1), consisting of several elements, e.g. cylinders, cubes spheres, with their axes in one or more planes. At least two supporting shells are made for lining (1) out of inexpensive material (2), e.g. by casting or forging to obtain cast iron or carbon steel shells with joint lines coinciding with the plane(s) of lining (1); and the inner surface of the shells covers the outer surface of the lining. Clamping and/or sealing methods are used to ensure non-slip joints between the lining and the shells, esp. by casting the shells round the lining, or explosion welding the lining onto the shells. The lining may have a smooth, rough, or grooved outer surface to assist bonding. The metal parts obtd. may have several combined functions. Corrosion resistant linings made of e.g. stainless steel Ti, Al, Cu, can be used in inexpensive, thick materials(2) which withstand operating pressures.