| 摘要 |
FIELD: mechanical engineering; valves and fittings. ^ SUBSTANCE: invention is designed for use in high-pressure gas mains for preventing back flow of gas. Proposed valve contains outer housing with inlet and outlet channels. Inner-shaped housing is rigidly secured in inner space of valve housing to form ring channel in form of Venturi nozzle. Shutoff member with working surface in form of part of sphere in contact with seat is installed in cone-shaped housing by means of displacement mechanism. Seat is made in form of ring with contact conical surface inscribing the seat into profile of ring channel. Displacement mechanism is provided with compression spring installed on rod. Rod moves in sliding bearings installed in guide bushing. The latter is rigidly secured in inner housing. Seat and inner housing are installed in ring slots made, respectively, on inner surfaces of inlet and outlet channels of outer housing. Seat and inner housing are fixed on surfaces of slots perpendicular to longitudinal axis of valve. Fixing is done by threaded fasteners. Seal is placed between seat and fixing surface. Said is placed between seat and fixing surface. Said seal is made of material featuring elastic deformation properties, for instance, graphite containing material. Guide bushing has union nut in ring groove of which made n end face part, scraper is installed in form of ring made of elastic material. Scraper is in contact with surface of rod. ^ EFFECT: improved reliability of valve owing to provision of stable sealing in process of its service life. ^ 2 cl, 4 dwg |
