The most significant feature of this design is to possess all the advantages of pressurized fire tube boilers whitin "small body", "high efficiency", "long durability life" and "complete & perfect burning" which minimizes the air pollution. (Smoke gases stay at Bacharach 3-4). Besides the pressure in its fire tube styas at acceptable levels which enables the burner fire easily and work without any trouble.)

IISSY-GK type boilers are steel welded construction and cylindirical design. They are insulated with glass wool and covered with prismatic galvanised steel.

It has a quite narrow body as its fire tube and smoke tube are located in seperate cylinders. They can be transported in two parts for higher capacities. They are manufactured according to TES (Turkish standarts) or DIN (German Standarts) and for 3 to 10 bars. There is a moderate pressure in the fire tube, therefore it is recomended to user high pressure burners; ie: 2800 rpm.