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ÜKYP/YP Automatic Fuel Loading, Central System Heating Boiler Usage and Maintenance Manual
Installation diagram with closed expansion tank
Systems with open expansion tanks:
It is placed on the top of the system, that is, on the roof, and works open to the atmosphere with a
level difference. An expansion tank is placed at a point slightly higher than the highest point of the
distribution system to collect the expanding water volume. The water that expands in the boiler is
stored in the expansion tank through the flow safety pipe. When the water in the installation cools
down, the decreasing water of the installation is completed by the expansion tank through the return
safety pipe. Since the expansion tank also opens the system to the atmosphere, it ensures the safety
of the system by preventing the pressure in the heating installation from rising above the atmospheric
pressure. The air in the system is evacuated by opening the vent pipes to the atmosphere from the
expansion tank. It is recommended to use separate expansion tanks for each boiler in the installation
according to their capacities. That is, it is not correct to connect two boilers to a single expansion tank.
There are flow and return safety pipes for each boiler and expansion tank. Valves, check valves etc. on
these safety pipes. No fittings should be installed. Safety pipes must reach the closest point of the
boiler inlet and outlet from the shortest vertical path. Movement from the horizontal path is
permissible only at the level of the expansion vessel and at a minimum length.
ÜNMAK solid fuel boilers should be connected to an installation with an open expansion tank in
accordance with the installation diagram shown below. The circulation pump can be connected on the
flow or return line. In case the pump is in the boiler return; The open expansion tank must be higher
than the head of the pump.
