Propane and butane bottles do not contain pressurized gas. The pressure in them depends on the temperature and quantity in the bottle. When the bottle is empty, it returns to a gaseous state. This means that if you have one open bottle and another one closed, the regulator will not work.

Propane and butane regulators come in various sizes. A 9kg cylinder is the most common, but there are other sizes available. Smaller bottles can also be used with gas hoses, but will need adapters. A typical 2kg bottle has a 3/8" threaded outlet. This will need an adapter that screws into a male to female 3/8" BSP gas hose.

There are many advantages to using a dual stage bottled LPG regulator, which requires less maintenance than a single stage. These units have two stages of regulation, which allows for safer pressure distribution. However, they should not be installed directly on an LPG cylinder. Always make sure that the regulator is mounted vertically.

Dual stage regulators have two regulators, one of which lowers the pressure of the gas supply. The second regulator reduces this intermediate pressure to a level that is acceptable to the user. These regulators are usually equipped with two safety valves to minimize the risk of explosion.