For petroleum refinery start-up hydrogen bullets (which supplies pressurized hydrogen to refinery) have to be filled up with pressurized hydrogen. Battery of cylinders having Hydrogen pressurized upto anywhere between 150 - 200 kg/cm2 (estimated) maybe used to pressurize the bullets (bullets are vessels storing pressurized liquid or gas). If you are a manufacturer and / or supplier of these hydrogen cylinder battery, please let us know the arrangement required to hook-up to the refinery supply piping. P&I drawings / write-ups previously supplied will give a better understanding. Early response will be appreciated. RegardsCountry:India