e4043070 rate contract for supply of fully machined unplated top flange (pvn 36) , rate contract for supply of top & middle flange for outdoor breaker for 18 months(valid from date of approval at bhel). , fully machined unplated top flange (pvn 36) to drg no. 25217001503-001 rev.24. (casting drg. 25217001516-001 rev.06). pvc ratio for aluminium is 1:3.7. base rate of aluminium alloy ingot ia10, as declared by nalco, is rs. 254.350/kg. , fully machined unplated middle flange (pvn 36) to drg no. 25217001595-var. 00, rev.05. (casting drg. 25217001518-001 rev.09). pvc ratio for aluminium is 1:4.6. base rate of aluminium alloy ingot ia10, as declared by nalco, is rs. rs. 254.350/kg.