RISER VALVE

摘要

A marine riser fill-up valve adapted to be connected to a riser extending through a body of water and to selectively open and close communication between the interior of the riser and the surrounding water. The valve comprises a housing (21) and a spool (22) within the housing (21). The spool (22) is adapted to move within the housing (21) between a closed position preventing communication between the interior of the riser and the water and an open position allowing communication between the interior of the riser and the water. The spool (22) and the valve housing (21) have respective one of a seal surface (29) and a seat (39). The seal surface (29) and seat are (39) adapted to form a sealing interface in a closed position of the valve. The valve comprises a water back pressure chamber (28) which is communicating with the riser interior when the valve is open and with the surrounding water when the valve is closed.