Marine riser fill-up valve

A marine riser safety valve adapted for connection in an offshore riser string through the sea comprising,

• a body having a bore therethrough forming a vertical flow path for drilling fluid through said riser string and having an outwardly facing depression formed in a first section of said body and at least one valve port formed in a second section of said body,
• at least one diaphragm port formed in the wall of said body between said bore and said depression, and
• deformable means disposed about the outside of said body to cover said depression and said valve port, and responsive to a pressure differential of a predetermined amount between the exterior of the deformable means and the interior bore of the body, for deforming radially inwardly into said depression while simultaneously moving to uncover said valve port.

A cylindrical member adaptable for use in a marine riser safety valve, the valve adapted for connection in an offshore riser string having a body having a bore there through forming a vertical flow path for drilling fluid through the riser string and having an outwardly facing depression formed in a first section of the body and at least one valve port formed in a second section of the body, a diaphragm port formed in the wall of the body between the bore and the depression, the cylindrical member comprising,

• a cylindrical diaphragm disposed about the outside of the body radially deformable between a relaxed state and a deformed state, and
• a cylindrical valve spool joined at one end to said cylindrical diaphragm,
• said cylindrical diaphragm adapted to move from said relaxed state, where said valve spool covers valve port in said safety valve, to said deformed state in radially inwardly into the depression response to a differential pressure between sea water on its outside and drilling fluid on the inside of said safety valve, where said valve spool simultaneously uncovers said valve port.