The Siamese connection and its connection to the dry riser and its use in extinguishing fires The Siamese connection is used as an additional source for extinguishing fires and is connected to the civil defense vehicle through which water is pumped to extinguish the fire. The siamese connection is called FDC = Fire Department Connection. The siamese connection is connected to what is called a dry riser that reaches each floor and is a 4″ pipe connected to the fire pump and a non-return valve is installed on it to prevent the pressurized water from returning again outside the system.. The dry riser is called by this name because it is free of water and it is at the end of the line from the top an automatic air release valve to remove air from the line when the water is pressurized Inside the dry riser. Even if a fire occurs and the water from the tank inside the building runs out, the siamese connection is connected to the civil defense vehicle to feed the sprinklers and fire hydrants, the landing valve.
