supply and refilling of hydrogen gas cylinders for generators of htps supply and refilling of hydrogen gas cylinders for generators of unit no. 7 and dtps, htps, kasimpur , supply & refilling of the hydrogen gas confirming as per is:1950-65 grade-i and purity 99.90% with latest amendment thereof and as per following composition: 1 ) water: 10 mg / m3 maximum 2 ) oxygen: 0.0010 % by volume maximum 3 ) co2: 10 %ppp volume maximum 4 ) hydrogen: 99.90% by volume minimum note: hydrogen gas will be filled in compressed condition at approx. 155-160 kg / cm2 pressure and temperature 15 ºc to be filled in empty cylinders. capacity of cylinders: 7 or 6 cubic meters.