Natural circulation steam boilers or also called natural circulation steam generators are available in different sizes with capacities from 200 to 2900 KW and operating pressures of 80 and 95 bar in vertical design.

ZAFA natural circulation steam boilers for high-pressure steam are built on the basis of the natural circulation boiler in three-pass design. Steam boilers of this series can functionally only be operated in vertical design, as they operate in a hermetically closed system without a feedwater pump. The prerequisite for this is 100% condensate return and a consumer (heat exchanger) which must be installed above the boiler unit.

Once treated, the boiler water serves as the heat transfer medium. It is circulated as steam and condensate and does not have to be constantly renewed as is the case with conventional steam systems, which largely eliminates the need for ongoing maintenance and thus significantly reduces operating costs.

Manufacturing takes place exclusively at ZAFA in accordance with the European Pressure Equipment Directive 2014/68/EU, the AD-2000 and EN 12952 regulations with TÜV approval (German Certification Authority) and CE mark.