Vent (submarine)
Encyclopedia
In submarine technology a vent is a valve
fitted to the top of a submarine
's ballast tanks to let air escape from the top of the ballast tank and be replaced by water entering through the open Kingston valve
s at the bottom of the tank.
When on the surface a submarine's ballast tanks are filled with air which gives the vessel its buoyancy
and in order for the submarine to submerge water is taken into the ballast tanks through the open Kingston valves in the bottom of the tanks, effacing this excess buoyancy. As the ballast tanks contain air when on the surface it is necessary to allow this air to escape, so that water may then enter the tanks, and this air is allowed to escape via the opened vents in the top of the ballast tanks.
The vents which are used to allow water to enter the submarine's main ballast tanks when it submerges are the main vents and it is air escaping though these that accounts for the spray
sometimes seen when submarines dive.
To get a submarine to surface, the main vents in the top of the tank are closed and high-pressure
compressed air
is blown into the ballast tanks, forcing the water out through the open Kingston valves at the bottom of the tank. This increases the vessel's displacement. When the weight of the displaced water becomes greater than the weight of the vessel, buoyancy becomes positive, and the submarine begins to rise.
Once on the surface, in order to conserve supplies of compressed air, a lower-pressure compressor
is then used to remove the remainder of the water from the tanks.
Valve
A valve is a device that regulates, directs or controls the flow of a fluid by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings, but are usually discussed as a separate category...
fitted to the top of a submarine
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...
's ballast tanks to let air escape from the top of the ballast tank and be replaced by water entering through the open Kingston valve
Kingston valve
A Kingston valve is a type of valve fitted in the bottom of a ship's fuel, water and ballast tanks. Named after its inventor John Kingston , an English engineer....
s at the bottom of the tank.
When on the surface a submarine's ballast tanks are filled with air which gives the vessel its buoyancy
Buoyancy
In physics, buoyancy is a force exerted by a fluid that opposes an object's weight. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus a column of fluid, or an object submerged in the fluid, experiences greater pressure at the bottom of the...
and in order for the submarine to submerge water is taken into the ballast tanks through the open Kingston valves in the bottom of the tanks, effacing this excess buoyancy. As the ballast tanks contain air when on the surface it is necessary to allow this air to escape, so that water may then enter the tanks, and this air is allowed to escape via the opened vents in the top of the ballast tanks.
The vents which are used to allow water to enter the submarine's main ballast tanks when it submerges are the main vents and it is air escaping though these that accounts for the spray
Spray
Spray can refer to:* Spray ** Aerosol spray** Blood spray** Road/tire spray, kicked up from a vehicle tire** Snow spray, a spray that creates artificial snow fall...
sometimes seen when submarines dive.
To get a submarine to surface, the main vents in the top of the tank are closed and high-pressure
Pressure
Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...
compressed air
Compressed air
Compressed air is air which is kept under a certain pressure, usually greater than that of the atmosphere. In Europe, 10 percent of all electricity used by industry is used to produce compressed air, amounting to 80 terawatt hours consumption per year....
is blown into the ballast tanks, forcing the water out through the open Kingston valves at the bottom of the tank. This increases the vessel's displacement. When the weight of the displaced water becomes greater than the weight of the vessel, buoyancy becomes positive, and the submarine begins to rise.
Once on the surface, in order to conserve supplies of compressed air, a lower-pressure compressor
Gas compressor
A gas compressor is a mechanical device that increases the pressure of a gas by reducing its volume.Compressors are similar to pumps: both increase the pressure on a fluid and both can transport the fluid through a pipe. As gases are compressible, the compressor also reduces the volume of a gas...
is then used to remove the remainder of the water from the tanks.