The most significant feature of this design is to provide quite easy firing of burner for start and to reach the desired capacity whitout overloading the burner. These features are maintaned by relatively low pressure in the smoke tubes.

ISSY-SD type boilers are steel welded construction and cylindirical design. They are insulated with glass wool and covered with galvanized steel. They are manufactured according to TSE (Turkish standart) or DIN(German Standart) and for 3 to 16 bars. All the inlets are controlled specially in orderr to provide gas leaking.