A gas bottle is a container used to hold compressed gases. They vary in size, shape and capacity but all share the same basic features of being designed for transport, storage and use in high-pressure environments. They are often referred to as gas bottles, LPG cylinders or BBQ gas cylinders but whatever name you give them it is important that you take proper safety precautions when handling them.
Liquefied petroleum gas (LPG) is the most common form of bottled gas available in New Zealand. It is supplied in small bottles which are attached to a regulator that can be clipped onto or screwed into the top of a barbecue gas appliance. The regulator controls the amount of pressure that the gas releases to the appliance and is vital for safe usage. It also helps to keep the gas cylinder at a low pressure so that it doesn’t explode.
The gas cylinders are painted in bright colours, usually yellow for propane and green for butane to make them easily identifiable. They may also be identified with a list of contents on the cap, or in a stamp on the side of the cylinder. Cylinders that do not contain medical-grade gases must be marked with their tare weight (the actual empty mass of the cylinder), which is calculated from the valve without product and preceded by the letters “TW”. Cylinders for industrial use are not required to be colour coded, but they should be clearly marked for identification.
There are many different types of gas cylinders available on the market and they are manufactured in a wide range of materials. In general, they are made of very strong steel or aluminium to withstand the high-pressure environments in which they are used. They are also designed to be easily handled and have a handle at the base of the cylinder for easy lifting. Some are also fitted with a tamper-proof cap for security.
Gas cylinders can explode if there is a leak in the cylinder or the connection between it and the regulator is loose. This can cause property damage and injury or even death. To prevent this, it is important to check your gas cylinders regularly for leaks, especially after you have emptied them or had them refilled. You should never attempt to forcibly open a gas bottle, and you should always be careful when lifting it.
When a gas bottle is close to empty, the indicator will change to red and the flow of gas stops when it is completely empty. It is advisable to have two bottles at home and to only turn on one at a time so that the other remains full as a backup. It is also worth checking the indicator after 12 hours with no appliances on so that if it does go red then you have plenty of time to order a refill.
A gas bottle cannot be taken to a filling station like a petrol pump for refilling so it needs to be returned to the supplier when it is empty. This is usually your local liquefied petroleum gas supplier, but it could also be a welding supply company or another bottled gas provider.