procurement of pourable insulation, castable refractory why thethe a and fire crete p, for boiler for unit no. 1 and 2 at 2x600mw. sstpp, mppgcl, dongalia , pourable insulation :- specification: service temp.- 650°c, permanent linear change at650 °c= + / - 2.0% , compressive strength- in kg / cm2 [ at 110 °c- 22 min., at 500 °c- 14 min. ] , bulk density at 110 °c ( kg / m3 ) = 660 max., bulk density at 500 °c ( kg / m3 ) = 640 max., thermal conductivity ( k ) [ at mean temp.-: 250 °c in kcal / m hr°c= 0.16 ( max. ) , 500 °c in kcal / m hr°c ] , chemical composition : fe2o3 ( ferite oxide ) : 5.0 ( max. ) , castable refractories why theate grade a , castable refractories fire crete p