A boiler feedwater pump is a specific type of pump used to pump water into a steam boiler. The water may be freshly supplied or returning condensate produced as a result of the condensation of the steam produced by the boiler. These pumps are normally high pressure units that use suction from a condensate return system and can be of the centrifugal pump type or positive displacement type. An electrically driven pump (electropump) for waterworks near the Hengsteysee, Germany. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... It has been suggested that this article be split into articles entitled steam and water vapor, accessible from a disambiguation page. ... A boiler is a closed vessel in which water or other fluid is heated under pressure. ... Water vapor condensing over a cup of hot tea Condensation is the change in matter of a substance to a denser phase, such as a gas (or vapor) to a liquid. ...

Construction and operation

Feedwater pumps range in size up to many horsepower and the electric motor is usually separated from the pump body by some form of mechanical coupling. Large industrial condensate pumps may also serve as the feedwater pump. In either case, to force the wate and are controlled by a float switch or other similar level-sensing device energizing the pump when it detects a lowered liquid level in the boiler. The pump then runs until the level of liquid in the boiler is substantially increased. Some pumps contain a two-stage switch. As liquid lowers to the trigger point of the first stage, the pump is activated. If the liquid continues to drop (perhaps because the pump has failed, its supply has been cut off or exhausted, or its discharge is blocked), the second stage will be triggered. This stage may switch off the boiler equipment (preventing the boiler from running dry and overheating), trigger an alarm, or both. Rotating magnetic field as a sum of magnetic vectors from 3 phase coils An electric motor converts electrical energy into mechanical energy. ... A condensate pump is a specific type of pump used to pump the condensate (water) produced in an HVAC (heating or cooling) or refrigeration system. ... A float switch is a device used to sense the level of liquid within a tank. ...

Steam-powered pumps

Steam locomotives and the steam engines used on ships and stationary applications such as power plants also required feedwater pumps. In this situation, though, the pump was often powered using a small steam engine that ran using the steam produced by the boiler. A means had to be provided, of course, to put the initial charge of water into the boiler (before steam power was available to operate the steam-powered feedwater pump). The pump was often a positive displacement pump that had steam valves and cylinders at one end and feedwater cylinders at the other end; no crankshaft was required. One of the last mainline steam locomotives built in the UK: British Railways Standard Class 9F 2-10-0 no. ... // The term steam engine may also refer to an entire railroad steam locomotive. ... A power station (also power plant) is a facility for the generation of electric power. ...

See also

• Injector