Closing device for check opening of e.g. flue gas pipe has two-piece cap for sealing surface flanks of tube end, fixed on pipe control opening, by elastic torus fitted in cap periphery when cap is rotated in axial direction to tube end

摘要

The device has nipple (2) fitted on control opening of the gas pipe, with sealing surface along its inside edges, is provided with a two-piece cap. The cap has a counter surface (12) along upper edge of the outer piece and also of inner piece. An elastic torus (14) expandable in radial direction is fitted in the groove of the cap periphery. The torus extends outwardly in radial direction by tightening the screwable knob (6-8) and vice versa. The slanting surface along the inner periphery of the nipple allows the torus to move outwardly in radial direction. The slanting surface is formed by a corrugation (17) provided in the inner wall of the nipple. An anti-twist device is provided to prevent mutual twisting of outer and inner component. The elastic torus is a worm spring coiled from steel wire.