Patent ID: 7143776

Claim:
Valve element ( 10 ), comprising a main body, at least one inlet ( 101 ) and at least one outlet ( 102 ), a passage connecting the inlet and outlet, at least one burst disk (rupture disk) ( 13 ) or equivalent, which, when unbroken, closes the passage from inlet to outlet, and a piston element ( 15 ) provided with a piercing element ( 14 ) for piercing the burst disk, characterized in that the piston element ( 15 ) is provided with a passage ( 17 ) for a pressure medium, said passage extending axially through the piston element from one first side to one second side, that the piston element is provided with a second burst disk or equivalent which, when unbroken, closes the passage ( 17 ) provided in the piston element, and that the device comprises means ( 19 , 22 ) for piercing the second burst disk ( 18 ).