... five toppest manufacturer of 58*1800 solar bolier,solar water heater with CE,Solar Keymark,CCC 1.Products series ModelCapacity( ... from Germany Bayer Company,whose inner tank,outer skin,end cap and insulation layer form a perfect heat-preserved cabin, ... holes for exhaust port, overflow, water inlet and outlet, electric heater is optionWelding:Argon arc weldingFastening pieces:stainless steel screw5.solar ...