Hatch for the opening and closing of pressurised pipes, in particular for the opening and closing of branch pipes for the introduction of pipe cleaning and inspection apparatus
A closing system for pressurized pipes, includes an annular supporting structure, designed to be secured to one end of the pipe, a closing hatch mounted on the annular support, and elements for locking the hatch including a locking ring inserted into an annular cavity in the support to lock the hatch, wherein the inside edge of the hatch is tapered to form an inclined wall for coupling to a corresponding inclined wall in the annular support. The collapsible ring includes a number of sectors, one of which is fixed and integral with the hatch, while the others are hinged to the adjacent sectors, so that they can rotate on a plane parallel with the hatch until they exit from the annular seating and allow the hatch to open. The hatch is opened and closed simply by rotating it around a hinge.
1. A closing system for pressurised pipes, comprising:
an annular supporting structure, to be welded or secured to one end of a pressurized pipe,
a closing hatch pivotally mounted on said annular supporting structure,
means designed to lock said hatch in a closing position, said means consisting of a locking ring inserted into an annular cavity in said support to lock the hatch,
said closing hatch having an inner wall designed to couple to a corresponding wall in said annular supporting structure, a seal being mounted on said inner wall of the closing hatch, or on said corresponding wall of said of said annular supporting structure,
said inner wall of said closing hatch and said corresponding wall of said annular supporting structure are inclined by 45° and are configured so that said closing hatch pivots open and closed only by rotation.
2. The closing system as claimed in claim 1 , wherein said locking ring is a collapsible locking ring mounted on the outer wall of the hatch, said collapsible locking ring comprising a plurality of sectors, one of said sectors is fixed and integral with the hatch, and others of said sectors are hinged to adjacent ones of said sectors, so that said sectors rotate on a plane parallel with the hatch until said sectors exit from said annular groove and allow the hatch to open.
3. The closing system as claimed in claim 2 , wherein said one of the sectors that is fixed is positioned close to the hinge of the hatch.
4. The closing system as claimed in claim 3 , wherein said sectors comprise one or more annular sectors that are hinged at either end to said fixed sector, said annular sectors being hinged to an articulated system consisting of two rods or connecting rods hinged together and to ones of said sectors, one of said rods being integral with an operating lever designed to control the movements of said sectors between a position in which they are arranged in said annular groove to form said locking ring as a continuous ring, and a position in which they exit completely from said annular groove.