POLYBARRIER CONNECTION UNIT FOR METAL PIPE LINES Russian patent published in 2002 - IPC

FIELD: construction of immovable union detachable joints for metal pipe lines of high-pressure pneumohydraulic systems handling high-flow, inflammable, explosive and chemically active media and in hard-to-get-at areas. SUBSTANCE: proposed connection unit has tubular body with chambers, connecting ring, locking and fastening devices, locking member which is coaxial relative to body and sealing gasket. Sealing gaskets are made in form of bimetallic rings provided with inner sealing layer made from metal which is similar to material of tubular body and locking layer which is made from more plastic and easily deformable metal as compared with material of tubular body at linear expansion coefficient closest to that of material of tubular body, connecting ring and locking member within working temperature range. Sealing surfaces of tubular body and connecting ring are provided with concentric circular chambers of trapezoidal section. Surfaces of these chambers are engageable with sealing gaskets. Each pair of chambers of one barrier make common form-shaping chamber of its sealing gasket. Volume of common chamber of first barrier is equal to volume of first sealing gasket. Volumes of common chambers of second and subsequent barriers are equal to or exceed volumes of respective sealing gaskets. Total length of each is less than length of respective sealing gasket in state before deformation during assembly of unit and sizes of bottoms whose thickness is lesser than of respective sealing gasket in state before deformation. Sealing surface of tubular body is provided circular projections for positioning sealing gasket and connecting ring; sealing surface of connecting ring is also provided with circular projections for positioning sealing gaskets; provision is also made for capillary tubular outlet for check of tightness of each sealing barrier terminating in capillary openings found in each space between chambers. EFFECT: enhanced tightness and corrosion resistance of unit; stabilized interaction of inner bimetallic ring with tubular body and connecting ting under conditions of external mechanical and thermal actions due to simultaneous deformation of external layer of ring, thus enhancing reliability. 3 dwg