... effect, the heat exchanger choose SUS304 stainless steel production, anti-corrosion, not deformation, thermal insulation layer advanced overall foaming technology ... alloy, 1.5mmInsulation: polyurethane frothing, 50mmVacuum tube: AL/N coating, 47*1500/58*1800mmAccessories: MG rod, electrical heating, ... vacuum tube was evacuated into the tank; the coating inside of tube can absorb more than 92% ...