Ventilanordning

A valve assembly to be used in a subsea structure 8, particularly a mudmat, has a valve closing disc (2) hung, with limited free play, from a support member (2). The support member is provided with pivotable connecting hooks (16) engaging with a flange (7) on the subsea structure, thereby securing the support member and valve closing disc to the subsea structure 8. By means of a central tightening screw (17) the valve closing disc may, when the hooks are in gripping engagement with to the flange, be pressed down so as to bear against a valve seat formed by the free annular surface (6) of the flange. In the open position of the valve assembly, the valve closing means are held in a position above the flange (7) by means of a rod (12) which extends downward from the valve closing means and penetrates a hub sleeve (11) in the aperture, and which may be locked in an open position there. When the through aperture 10 in the subsea structure is to be be closed, the holding engagement between the rod (12) and the hub sleeve (11) is released and the support member (2) and valve closing disc will then sink down toward the flange, whereby the connecting hooks (16) achieve underlying gripping engagement with the flange.