... of steam pervasion are all lower than those of other board heat preservation materials and they have the characteristics of strong ... ,frost resistance of the high way,railway ,airport,square and household fitment.It is the generally acknowledged the best heat preservation ... power (kw) 33 52Driving motor power(kw) 55 55Thickness of board (mm) 20,50,30,40,50,60,75,100Width of ...