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Pressuretrol
{{unreferenced, date=December 2012 A pressuretrol is a control used to control a steam boiler, by setting when the boiler should begin and end firing based on steam pressure. The pressuretrol is generally secondary to another control, such as a thermostat(generally in smaller buildings) or outdoor-reset controller- If this controller is not calling for heat, the pressuretrol will not activate the boiler. Settings Pressuretrols have 2 settings: A main cut-in or cut-out setting (depending on model), and a differential setting (which is either additive or subtractive, and usually stated on the controller). The main setting is accessible from the outside of the controller, but the differential is often located inside the controller box, and typically the cover must be removed by removing a screw to access the differential control. If the main setting is a cut-in setting, then the differential setting sets the cut-out setpoint by adding to the cut-in setting(additive), and if the main se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boiler
A boiler is a closed vessel in which fluid (generally water) is heated. The fluid does not necessarily boil. The heated or vaporized fluid exits the boiler for use in various processes or heating applications, including water heating, central heating, boiler-based power generation, cooking, and sanitation. Heat sources In a fossil fuel power plant using a steam cycle for power generation, the primary heat source will be combustion of coal, oil, or natural gas. In some cases byproduct fuel such as the carbon monoxide rich offgasses of a coke battery can be burned to heat a boiler; biofuels such as bagasse, where economically available, can also be used. In a nuclear power plant, boilers called steam generators are heated by the heat produced by nuclear fission. Where a large volume of hot gas is available from some process, a heat recovery steam generator or recovery boiler can use the heat to produce steam, with little or no extra fuel consumed; such a configuration is common ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Domestic Hot Water
Water heating is a heat transfer process that uses an energy source to heat water above its initial temperature. Typical domestic uses of hot water include cooking, cleaning, bathing, and space heating. In industry, hot water and water heated to steam have many uses. Domestically, water is traditionally heated in vessels known as ''water heaters'', ''kettles'', ''cauldrons'', ''pots'', or ''coppers''. These metal vessels that heat a batch of water do not produce a continual supply of heated water at a preset temperature. Rarely, hot water occurs naturally, usually from natural hot springs. The temperature varies with the consumption rate, becoming cooler as flow increases. Appliances that provide a continual supply of hot water are called ''water heaters'', ''hot water heaters'', ''hot water tanks'', ''boilers'', ''heat exchangers'', ''geysers'' (Southern Africa and the Arab world), or ''calorifiers''. These names depend on region, and whether they heat potable or non-potable w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquastat
An aquastat is a device used in hydronic heating systems for controlling water temperature. To prevent the boiler from firing too frequently, aquastats have a high limit temperature and a low limit. If the thermostat A thermostat is a regulating device component which senses the temperature of a physical system and performs actions so that the system's temperature is maintained near a desired setpoint. Thermostats are used in any device or system tha ... is calling for heat, the boiler will fire until the high limit is reached, then shut off (even if the thermostat is still calling for heat). The boiler will re-fire if the boiler water temperature drops below a range around the high limit. The high limit exists for the sake of efficiency and safety. The boiler will also fire (regardless of thermostat state) when the boiler water temperature goes below a range around the low limit, ensuring that the boiler water temperature remains above a certain point. The low li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control Devices
Control may refer to: Basic meanings Economics and business * Control (management), an element of management * Control, an element of management accounting * Comptroller (or controller), a senior financial officer in an organization * Controlling interest, a percentage of voting stock shares sufficient to prevent opposition * Foreign exchange controls, regulations on trade * Internal control, a process to help achieve specific goals typically related to managing risk Mathematics and science * Control (optimal control theory), a variable for steering a controllable system of state variables toward a desired goal * Controlling for a variable in statistics * Scientific control, an experiment in which "confounding variables" are minimised to reduce error * Control variables, variables which are kept constant during an experiment * Biological pest control, a natural method of controlling pests * Control network in geodesy and surveying, a set of reference points of known geospatial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
