procurement of various spares sealing rings and o rings of hydraulic valves for units 1 and 2 2x210 mw sgtps mppgcl birsinghpur , u sealing ring for esv , u sealing ring for hpcv , guide bush for iv , torsion spring for over speed trip release unit , compression spring for esv sm , sealing ring 130x150x10 for hpcv , sealing ring b 40x60 for hpcv & lpbp valve , sealing ring b50x75for ipcv , sealing ring a22x27for lpbp feed back , sealing ring a40x60 for hpcv & lpbp valve , sealing ring a50x70for ipcv & lpbp sm , sealing ring a50x75 for ipcv , sealing ring d50x70for esv & iv sm , o-ring 5x2 . 5for assly of extraction valve relay , o-ring 10 . 8x3for lpbp cv pilot valve , o-ring 28x3for esv &lpbp sm , o-ring 59x3for thrust brg trip device , o-ring 74x3for lpbp sm , o-ring 85x4for assly of extraction valve relay , o-ring 108x3for hpcv sm , o-ring 203x3for crh nrv sm , o-ring 380x4for hp& ip cv sm , o-ring 530x5for esv sm , o-ring 640x8for lpbp sm