The cast iron slide valve block f115 is designed to regulate the intensity of combustion by changing the level of draught in the chimney. It has a handle for controlling the gate valve with the possibility of access to the furnace room. It allows to keep heat in the stove after the cessation of active combustion and increase the service life of the chimney. It is installed on the Gefest cast iron starter pipes with the length of 500mm. Then the first element of the chimney system, such as a starter or boiler adapter, is installed on the spigot of the slide block.