Temporary obturation panel of a passage inside a vessel accessible only through an orifice of smaller size

Abstract

The invention relates to a temporary sealing obturation panel, inside a vessel accessible only through a manhole, of a passage provided on its periphery with a support collar. It is constituted by: panels articulated by flexible fluid-tight hinges, bordered by lines of latching pins, stiffeners comprising lines of holes conjugate with the lines of pins, a frame in at least two articulated parts, with means for gripping the ends of the panels and the stiffeners against the support collar. The invention is applicable to the closing of primary circuit ducts opening into the water box of a steam generator of a pressurized water nuclear boiler.

We claim: 
     
       1. Temporary fluid-tight obturation panel for a passage into a vessel accessible only through an aperture of dimensions less than those of the passage to be obturated, the periphery of the passage to be closed comprising a support collar provided with threaded holes, said obturation panel being constituted by: at least two panels articulated together by flexible fluid-tight hinges, the size and number of panels being determined to enable passage through the access aperture of the set of panels folded on one another, each panel comprising along its articulated edges a series of latching pins,   a set of stiffeners equal in number to that of the hinges of the panel, each stiffener comprising two lines of holes conjugate with the lines of the latching pins of two contiguous panels,   a frame in at least two parts articulated and foldable on one another, reproducing in folded position the contour of the support collar and comprising means to grip, with the interposition of a seal, the ends of the panels and of the stiffeners against the support collar, by screwing into the threaded holes.   
     
     
       2. Obturation panel according to claim 1, wherein the panels are constituted of light metallic alloy coated with carbon fibers bonded by resin. 
     
     
       3. Obturation panel according to claim 1, wherein the flexible hinges are formed of corrosion-resistant elastomer. 
     
     
       4. Obturation panel according to any preceding claim, comprising, associated with each hinge, a supporting sectional element interposed between the flexible hinge and the corresponding stiffener.