RUL is a critical property for refractory bricks, which basically reflects the service temperature of the bricks, raw materials, etc . ( Refractoriness Under Load ) RUL values ( T0.6 @ 0.2MPa ) for fireclay-based refractory bricks are usually below 1500 �C . for medium duty fireclay bricks only at about 1300 �C, high duty fireclay bricks at 1350 to 1420 �C, superduty fireclay bricks between 1420 and 1500 �C ( sometimes even higher than 1500 �C ).
