A float chamber is a device for automatically regulating the supply of a liquid to a system. It is most typically found in the carburettor of a normally aspirated internal combustion engine

Internal combustion engine

The internal combustion engine is an engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber. In an internal combustion engine, the expansion of the high-temperature and high -pressure gases produced by combustion apply direct force to some component of the engine...

, where it automatically meters the fuel supply to the engine. However, this arrangement is found in many automatic liquid systems, for example the cistern

Cistern

A cistern is a waterproof receptacle for holding liquids, usually water. Cisterns are often built to catch and store rainwater. Cisterns are distinguished from wells by their waterproof linings...

 of a toilet

Toilet

A toilet is a sanitation fixture used primarily for the disposal of human excrement, often found in a small room referred to as a toilet/bathroom/lavatory...

 could be said to be a type of float chamber.

A float chamber works by allowing liquid within the chamber to lift a float which is linked to a valve

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...

 which regulates the liquid intake. When the level is low, the float drops and opens the valve, allowing in liquid until the float rises sufficiently to close off the valve again. This is identical in principle to the ballcock

Ballcock

A ballcock is a mechanism or machine for filling water tanks, such as those found in flush toilets, while avoiding overflow and backflow. The modern ballcock was invented by Joseph Bramah and Thomas Twyford..The diagrams and description ONLY apply to the USA...

 valve.

One drawback of the basic type of float chamber described is that it only operates correctly when it is the right way up, so more sophisticated solutions are needed in aircraft

Aircraft

An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

.