Maintain and troubleshoot piped heating systems
Some steam-heat pipe systems employ a one-pipe distribution network. A single pipe serves both supply and return for each radiator. Steam rises from the boiler to the radiators, distributes heat and condensates to water. The condensate drips back down the same pipe to a return key. This feeds the boiler with water for the next cycle of steam are cooked.
Most hot water, and some steam systems use a two-pipe network though. Water or steam flows through the radiation units and returns through separate piping. Expansion tank serves as a cushion, so that the water pressure to increase, which make it easier to circulate.
In a “series” system, steam or water flows from one radiation unit to the next; There are no mains voltage. Disabling a radiator stops the flow of steam or water, making the stop of all other units.
