The SJB system is used to discharge flue gas based on the use of atmospheric circulation with an open combustion chamber. Chimneys are designed to work in dry conditions and up to a maximum temperature of 450 ° C.

These systems are used to remove flue gas from gas and oil boilers. Chimneys of these types are made of steel with a thickness of 0.5-0.6 mm, type 1.4521. Socket connections guarantee tightness of the system without the need to use gaskets.