Valve for gas cylinder with check-valve preventing unofficial refilling

Abstract

A valve for a gas tank, comprising a body comprising an engaging portion for sealingly engaging with a gas tank, a gas inlet, a gas outlet, and a gas passage fluidly connecting the gas inlet and the gas outlet; a shut-off device in the gas passage; a check-valve comprising a check-valve seat in the gas passage; a check-valve obturator configured for contacting the check-valve seat and thereby closing the gas passage in the presence of a refill gas flow from the gas outlet to the gas inlet; wherein the check-valve seat is resiliently urged against the body and configured to move away from the body so as to open the gas passage when subjected to a refill differential pressure reaching a predetermined threshold.

Dependencies are inferred from the claim text.