supply of refilling of cylinder with ultra pure iolar grade-ii nitrogen gas in 47 liters water capacity cylinder which contain 7 cum of gas in each cylinder. note: (i) delivery period shall be 18 months from po issue date. (ii) delivery may be in part as and when required and by the supplier. (iii) gas purity certificate & explosive certificate for cylinder from nabl certificate lab is must.refilling of cylinder with ultra pure iolar grade-ii nitrogen gas in 47 liters water capacity cylinder which contain 7 cum of gas in each cylinder. note: (i) delivery period shall be 18 months from po issue date. (ii) delivery may be in part as and when required and by the supplier. (iii) gas purity certificate & explosive certificate for cylinder from nabl certificate lab is must.,refilling of cylinder with ultra pure iolar grade-ii nitrogen gas in 47 liters water capacity cyl inder which contain 7 cum of gas in each cylinder. note: (i) delivery period shall be 18 months from po issu e date. (ii) delivery may be in part as and when required and by the supplier. (iii) gas purity certificate & ex plosive certificate for cylinder from nabl certificate lab is must. [ warranty period: 30 months after the d ate of delivery ] ]