procurement of 200 nb double disc valve for silo at ash handling plant at 2x600 mw sstpp, dongalia, distt. khandwa procurement of 200 nb double disc valve for silo at ash handling plant at 2x600 mw sstpp, dongalia, distt. khandwa , 200 nb double disc valve for dry ash technical specification / requirement to be fulfilled / supplied are as follows:- - dry ash temperature-70 degreec to 90 degreec - end cover- cast iron fg 260, hd 200-220bhn - disc wear resistance alloy casting as per astm a532 class iii type a hd 600bhn - seat ring wear resistance alloy casting as per astm a 532 class iii type a hd 600bhn - gland:- gun metal - gland packing 12mm gland rope - pin en31 - hardness 450 bhn - disc drive :- carbon steel - spring : spring steel - fasteners-hdf - gaskets-caf - spring - spring steel - cylinder- pneumatic 150x220 stroke dimensions - size / nb-200 - p.c.d -298 - no. of holes - 08 nos.