08-07-2019, 10:56 AM
"There are valves placed low in the water space, usually along the outside of the water space of the sides of the firebox, that can be opened to allow the water to escape (quite violently) and in that process it takes some of the sediment with it. It also reduces the amount of water in the boiler and that MUST be replenished with more water. In that process, the concentration of impurities in the water goes down on the whole (less water in the boiler that has a high concentration of impurities, plus more water that has less impurities) and so less material is available to precipitate out and collect on the boiler interior."
