Abstract: A rotary servo valve comprising a housing portion (105) defining a cylindrical cavity (107) and a first layer of ports. The rotary servo valve further comprises two opposing indented sides and two opposing sides having an increased radius relative to the indented sides, each side of increased radius extending between the two indented sides. The spool portion (103) is mounted for rotation relative to the cylindrical cavity (107), from a neutral position so as to prevent fluid flow through the valve, to an open position in which a fluid flow path is provided.

Abstract: A rotary servo valve comprising a housing portion (105) defining a cylindrical cavity (107) and a first layer of ports. The rotary servo valve further comprises two opposing indented sides and two opposing sides having an increased radius relative to the indented sides, each side of increased radius extending between the two indented sides. The spool portion (103) is mounted for rotation relative to the cylindrical cavity (107), from a neutral position so as to prevent fluid flow through the valve, to an open position in which a fluid flow path is provided.

Abstract: A corrugated pallet top and a method of assembling a corrugated pallet top that is produced from a single sheet of corrugated material.

Abstract: A process for recovering a base oil of lubricating viscosity from used oil in which, following optional pretreatment, used oil is re-refined by distilling it in distillation apparatus having multiple theoretical plates. Impurities are then extracted from the lube range distillate fraction or fractions with a liquid extractant such as N-Methyl-2-Pyrrolidone (NMP) at a temperature below the temperature, if any, of complete miscibility of the extractant and the oil. The oil and extractant are then separated whereupon the extractant is re-used in the process and the oil is subject to further treatment, as necessary, for targeted uses.