Abstract: Disclosed is a 2/2 directional seal valve with direct control comprising a housing and a seat piston installed, i.e., located, in leakproof and slidable manner in the housing. The piston has a conical surface which acts together with a seating surface located in the housing to open and close a passageway for passing pressure medium therethrough. A closing spring is also provided. One end of the closing spring bears against the housing and another end of the closing spring bears against the seat piston. In order to achieve a valve of this type which, while functioning in a leakage-free manner, has a low weight and is especially suitable for use in aircraft hydraulics. The seat piston comprises a high-strength carbon-fiber-reinforced plastic and the housing comprises light metal or a light metal alloy.

Abstract: A method of manufacturing plated hollow metallic blocks for further processing into seamless tubes of the type in which a body is immersed one or more times into a melt includes: protecting the inner surfaces of a hollow body of plating material against the admission of a melt of support material during the immersion of the hollow body in the melt of support material; immersing such hollow body formed of plating material into the melt of support material; removing the hollow body from the melt of support material; and crystallizing a layer of support material on the outer surface of the hollow body.

Abstract: A dispersion of a polymer such as an acrylic resin, and of a surface-acting resin, such as a melamine resin, is added to a cement mortar having a sand-to-cement ratio of 1 to 3 and a water-to-cement ratio of 0.25 to 0.35, the resin being preferably approximately 10 parts by weight per 100 parts of cement. This blend is applied to the interior of a pipe and the pipe is rotated at a speed which is gradually increased in order to produce at least approximately 20-g forces on the material for compacting same for a few minutes.

Abstract: A transport belt is constructed from a toothed belt as base with individual carrier elements separated by spacers. These elements each have a shallow trough with central indent and tapered base.