SZS Series Fuel and Gas Boiler is designed by our company with double drums. This water tube boiler is in vertical structure and “D ... ,Weishaupt Heat Rate: 92%-97% SZS Series Oil and Gas Boiler Features 1 with double drums and “D” type layout, compact structure ... Oil, Residual Oil, Natural Gas, City Gas, and Blast Furnace Gas can be used as Fuel. Widely used in chemical industry, plastics industry, ...