Die Ethoxysilane (I), (IV) oder (VI), im Überschuß eingesetzt, reagieren mit Ethyl‐diazoacetat (II) zu den silylierten Essigsäureestern (III), (V) oder (VII).

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Bei der Einwirkung des Diazoacetats (II) auf die Hydridsilane (I) erhält man Derivate der Silylessigsäure (III).

After appraising the prospects for improvements in the control and use of gas at factories in the ferrous metallurgy sector, the company Lengipromez -a general contractor involved in the reconstruction of worn-out open-flow gas turbines and blast-furnace-gas lines -decided that it was necessary to design a special valve for gas lines. The company undertook its first gasworks reconstruction project at the f'mn Severstal'. The goal of the reconstruction was to save energy resources and make more efficient use of the factory's available blast-furnace gas.It was necessary to design a wedge-shaped valve with a sliding spi.ndle as the shutoff device. Such valves had proven themselves to be safe and reliable, having been used for many years on blast-furnace-gas lines at ferrous metallurgy plants.However, they were now being redesigned to operate with new parameters: a pressure of 0.25 MPa, a working-gas temperature of 200~ The new valve was also to have a class-I tightness rating. In addition, it was necessary to take into account the specific service conditions of the valve -the ability of the working gas to unde~o coking, accompanied by the precipitation and adhesion of coking resins in the through section of the valve and on the surfaces of the metal parts.The company Dneprotyazhmash developed specifications for and built gas valve DN2000 Pn25/30NZh911NZh. The valve meets the above-mentioned requirements and has the following main parameters: The valve was designed in accordance with GOST 5762-74, GOST 12.2.063-81, and the Safety Regulations on the Control and Use of Gas which are in effect for factories in ferrous metallurgy. It consists (Fig. 1) of a body 1 and a cover 2, both of which are made from rolled plate and are provided with stiffening ribs. The through part of the body contains two sealing surfaces hard-faced with corrosion-and wear-resistant alloys, the middle part of the body contains two unions to supply steam, and the lower part of the body contains two openings to remove gas-cleaning products. The lower part is also provided with a support.The upper part of the cover includes a throat for the passage of the spindle and the installation of a packing gland, while the lower part has a seat for the gland. The seat, which is hard-faced with a corrosion-resistant alloy, isolates the chamber containing the gland from the valve cavity. The lower part of the cover has a rectangular flange for connection to the body of the valve. The upper part of the cover includes an area for attachment of the column of the system.The band 3 transmits torque from the drive to the sliding nut which moves the spindle. The nut has trapezoidal inside threads and metric outside threads. Two thrust bearings are provided to take up the axial loads inside the band.Joint-Stock Company Dneprotyazhmash.