2212.     MAXTED, E. B.  Employment of High Pressures in Chemical Industry.  Jour. Soc. Chem. Ind., vol. 45, 1926, pp. 366-370T; Chem. Abs., vol. 20, 1926, p. 2712.

        High pressures are used (1) to increase reaction velocity, (2) to change equilibrium conditions, (3) to influence the course of a reaction, and (4) to facilitate heat transfer.  Joints should be tongue and groove with metallic or vulcanized-fiber gaskets.  Pipe joints should be flanged, with the end of the pipe projecting slightly to form the actual joint.  Sliding parts can only be packed by some form of leather bucket.  Internal heaters may have their leads carried through vessel walls by bolts in fiber sleeves with fiber gaskets protected by steel washers under the nuts.  Thermocouple leads are passed through fiber tubes in the wall and the gland, with a disk of fiber under the gland as packing; or they may have a metal disk soldered to the wire and packed in the stuffing box by fiber washers above and below the disk.  Brief mention is made of the significance of high pressures in the synthesis of NH₃, CH₃OH, “synthol,” H₂ from H₂O and Fe, isopropyl alcohol, and hydrogenation of naphthalene.