GB598971A - An improved manufacture of corrosion-resistant conduits and the like - Google Patents

Abstract

598,971. Making composite pipes. ARNOLD, J. C. (Standard Oil Development Co.). May 25, 1945, No. 13188. [Classes 83 (i) and 83 (ii)] Casting composite articles; casting pocesses.-A method of making conduits for corrosive fluids consisting of an inner rigid corrosion - resistant pipe separated from an outer pressure - resistant casing by a corrosion - resistant material, comprises mounting the inner pipe concentrically within the outer casing by clamping means at each end so as to form an annular chamber, one end of which is closed by one of the clamping means and pouring into the chamber a liquid corrosion-resistant material and allowing it to solidify. An inner lining of structural carbon 10 is held concentrically within an outer steel tube 50 by means of upper and lower clamping members 30, 20, connected by a rod 40. The inner surface of the steel tube is previously cleaned and tinned and the whole structure is heated by gas burners 70, or electrically, and molten lead is poured into the annular space 60. The lower clamping member 20 is formed with an annular recess 62 adapted to close the lower end of the annular space and to form a radial flange at the end of the cast insert. The upper clamping member 30 has radial lugs bearing against the outer casing but leaving the annular space partly uncovered. After pouring, the heating is cut-off progressively so that the lead cools from the bottom to the top, additional lead being poured in to make up for shrinkage. After casting, the upper end of the conduit is cropped to remove dross, screw-threaded and a pipe flange is attached, the face of the flange being covered with lead by burning or bonding and this covering is burned on to the annular lead layer of the conduit. The ends of the carbon lining are cemented to the lead lining. Instead of lead, porcelain in liquid form may be poured into the annular space and allowed to solidify, and in that case, an inner rigid tube of porcelain could be used instead of carbon. Specification 586,245, [Group XXVIII], is referred to.