9kg gas bottle vs 8.5kg Gas Bottle (What's the Difference?) (2023)

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  • Last Updated: 30 October 2022

Do many people wonder why some BBQ gas bottles are labelled as “9kg” while others are labelled as “8.5kg” when they look the same?

The fact is that they are the same.

Then, the obvious question is “Why are they labelled differently?”

9kg Gas Bottle

A 9kg gas bottle is considered the standard size BBQ gas bottle and is roughly equivalent to a 20 lb propane tank. LPG is called Propane in the United States, while Butane is also classified as liquified petroleum gas. 9kg represents the nominal weight of the gas contents. A 9kg gas bottle weighs approximately 17.5 kg when full, so it is very portable.

Variation is the Norm – No Standard Sizing

9kg gas bottle vs 8.5kg Gas Bottle (What's the Difference?) (2)

The filling of nominal “9kg” bottles with 8.5kg of gas was a safety initiative of the Australian LPG industry.

The same is true of “4kg” bottles being filled with 3.7kg of gas.

But why?

Unfortunately, many LPG bottles are labelled as 9kg or 4kg that are manufactured undersize, with less than the labelled capacity.

This is a result of the manufacturing and design variances amongst the many manufacturers of gas bottles that are imported, into Australia, from many countries around the world.

Surprisingly, Australia has no mandatory standard sizing, so they are all approved for sale.

20% Oversized for Expansion

9kg gas bottle vs 8.5kg Gas Bottle (What's the Difference?) (3)

LPG bottles are designed to be full while allowing 20% of the space, called “ullage”, for the natural expansion of the LPG.

Filling undersized bottles to a full 9kg or 4kg, thus leaving less than 20% ullage, would create a safety issue.

(Video) Propane gas bottle explosion

Overfilling can result in gas venting from the pressure relief valves.

This is especially true in the warm Australian climate.

Between a Rock & a Hard Place

However, filling undersized gas bottles correctly and safely meant that the Australian suppliers were misrepresenting the contents as 9kg or 4kg when it was less.

This put the industry in the untenable position of being either unsafe or misrepresenting the quantity of gas provided.

Neither of these options was acceptable.

The Solution

The solution was to take into account the cylinder size variations and standardise on 8.5kg and 3.7kg refills.

This allows for the size variances between bottles and prevents any unsafe overfilling.

To make sure that consumers are fully informed, the bottles are labelled accordingly.

What About Refilling Instead of Swap?

UnlikeSWAP’n’GO®bottles, which are filled by weight on digital scales, refilling is done by decanting.

The operator fills the bottle until some starts leaking out of the bleed screw.

Refilling can result in either overfilling or underfilling, as well as correct filling, depending on the gas cylinder and the operator filling it.

Dip Tube Variations

9kg gas bottle vs 8.5kg Gas Bottle (What's the Difference?) (4)

In addition to the cylinder size variances, there can be variances in the dip tube lengths.

Dip tubes can even be missing or have fallen out of the bottom of the valve.

The accompanying picture shows some examples.

Dip tube lengths are important because they are connected to the bleed screws.

The refill operator opens the bleed screw and fills the cylinder until the level of LPG reaches the bottom of the dip tube, at which point liquid LPG will start to bleed out.

This is his signal that the cylinder is full.

(Video) How To Tell If A Gas Bottle Is Empty - Team Member Hints & Tips - Bunnings Warehouse

If the operator is slow to stop the flow, the result can be dangerous overfilling.

Long dip tubes can result in underfilling.

Short or missing dip tubes will cause overfilling.

A missing dip tube is a worst-case scenario, as the entire ullage space would be filled, allowing no room for expansion.

This is one of the reasons thatswap is a much safer alternative, as dip tube variances have no effect when filling by weight.

10 Reasons Why Swap is Better than Refilling

Why should you use swap instead of refilling?
The simple answer is that you are getting much more than just the gas…

Here are some examples of the extra services* provided to swap customers:
9kg gas bottle vs 8.5kg Gas Bottle (What's the Difference?) (5)

1. The gas bottles are collected from your local dealer and transported back to the processing plant.

The gas bottles are then washed to remove any dirt or BBQ grease.

2. The gas bottles are refurbished to ‘nearly new’ condition.

With the largest supplier, over 50% of the gas bottles are repainted before refilling.

Gas bottles with heavy rust are shot blasted down to the bare metal and then primed and repainted.

3. Most accept out-of-date gas bottles at no extra charge.

They check the inspection date on every gas bottle before filling it.

They only refill those with valid test dates.

4. If a gas bottle has reached its expiry, they perform all of the required inspections, refurbish it, put in a brand new valve and then apply a new date stamp.

For more information on gas bottle testing, please see Gas Bottle-Cylinder Testing Facts.

5. They recycle thousands of gas bottles every year that do not meet their quality and safety standards.

9kg gas bottle vs 8.5kg Gas Bottle (What's the Difference?) (6)

(Video) Refill Propane LPG bottle at home from another cylinder & save money easy

They also make them ‘safe’ for recycling by removing any traces of gas so that our recycling friends can stay safe, too.

Please also see:

6. They use digital scales to ensure proper and safe filling based on weight.

They set the scales for each gas bottle, based on its empty (tare) weight.

This avoids dangerous overfilling or lost value through underfilling.

With swap, you know you are always getting what you pay for.

7. They typically perform two leak checks on each gas bottle.

The largest supplier has a safety record that is second to none.

Nothing is more important to them than the safety of their customers, employees and the community.

9kg gas bottle vs 8.5kg Gas Bottle (What's the Difference?) (7)

8. They cover the gas bottles with protective netting to help prevent scrapes and scratches during transport.

The largest supplier applies a yellow quality assurance seal around the gas bottle collar so you know that the gas bottle was filled and safety checked.

9. The gas bottles are transported to and from their refurbishment and filling plants so that you get a ‘nearly new’, fully inspected, accurately filled and leak-checked gas bottle ready to go, with no waiting.

10. Swap is available Australia-wide, from about5,000 locations, so you should never have far to drive.

BBQs and gas appliances

9kg gas bottles are lightweight, portable, and used for a wide range of applications. LPG is condensed into a power-packed energy source, and here are some examples of how long a 9kg cylinder will last.

  • 26 – 29 hours with 1 Burner on a Full Sized BBQ
  • 6 – 7 hours with 4 Burners on a Full Sized BBQ
  • 44 – 59 hours with 1 Burner on a Compact BBQ
  • 22 – 29 hours with 2 Burners on a Compact BBQ
  • 12 hours with 35 MJ Patio Heater
  • 36 hours with 12 MJ Table Top Heater

These estimates on how long a gas bottle last are based on running at maximum setting/rate. A 9kg gas bottle will last longer on a lower setting. 9kg gas bottles are used for BBQs, outdoor heating, camper cookers, iceboxes, camp lighting, motorhome stoves, fridges/freezers and a whole lot more.

Safe use of LPG for your BBQ

Heavy-duty 9kg gas bottles, such as Gasmate bottles, are ideal for portable BBQs. However, liquid Petroleum (LPG) is highly volatile and a 9kg gas bottle should only be handled by a responsible adult. Here are 5 safety considerations.

(Video) New and improved connection valve on SWAP'N'GO gas bottles!

Safe LPG gas cylinder storage – Store the gas bottle in a well-ventilated space, upright and away from any ignition source. If possible, use a gas bottle holder to ensure your cylinder doesn’t get knocked over. Never store LPG gas bottles indoors or in an enclosed environment.

Placement of your BBQ – Ensure there is enough ventilation and the BBQ is situated a safe distance away from flammable objects. Children should also be kept at a safe distance. If camping, make sure your gas bottle BBQ is placed at a distance from awnings, gazebos, tents, sleeping bags, swags, tarps, flammable adhesives, etc.

Transporting gas bottles safely – When transporting your gas bottle in a vehicle, make sure the bottle is firmly turned off and is securely stowed in an upright position. Don’t leave the cylinder in a hot or enclosed vehicle.

Checking your gas BBQ – Always use the correct hose and don’t modify any connections. Damaged hoses or regulators should be replaced. Check hoses for blockages and ensure all connections are snug fitting and secure.

Operating a BBQ gas bottle – Make sure the gas bottle is upright and on a stable base in a position where there is adequate ventilation. Always turn off the gas bottle valve when the BBQ is not in use, even if you think the gas bottle is empty. Don’t operate an LPG bottle while carrying a potential ignition source such as a mobile phone or battery-operated headlamp.

Maintaining your BBQ – You can check leaks in the hose line, adaptors, couplings, fasteners and connectors by running soapy water along the line while the gas cylinder is turned on. Clean the BBQ after every use, apply a light coat of cooking oil to prevent rusting and keep the BBQ grill covered when not in use.

BBQ gas refills

SWAP’n’GO gas bottles are the trusted choice for BBQ gas refills. SWAP’n’GO 9kg and 4kg cylinders are available at thousands of refill locations Australia-wide so you never need to run out of gas. Wherever you are in NSW, VIC, QLD or any other Australian state or territory, there’s bound to be a SWAP’n’GO refill station near you.

SWAP’n’GO 9kg gas cylinders are regularly cleaned and serviced to ensure they are in as-new working order for complete customer satisfaction. Service features include:

  • Simple swap and go exchange
  • No waiting around for a bottle refill
  • Your new bottle has been inspected, tested and safely filled
  • Your new gas bottle is fitted with a safety plug
  • Swap any brand of BBQ bottle
  • The 4kg or 9kg LPG gas bottle is yours to keep

Checking gas bottle level

Finding out how much gas is left in your gas bottle is easy – but first comes the basic science. To turn from liquid to vapour, liquid LPG draws heat from the steel gas bottle. This makes the gas bottle feel cold compared to the outside temperature. When using gas, the bottle can get cold enough for ice to form on the outside the bottle. Find out how much gas is left in a few simple steps.

1. Fill a bucket with hot water (not boiling).

2. Slowly pour the warm water down one side of the gas bottle.

3. A line of condensation may appear, indicating the gas level. If not:

3. Wait a few seconds then feel the side of the gas bottle where the water was poured.

4. The bottle should feel noticeably cooler at the level of gas.

5. If you feel no difference, the gas bottle may be empty.

Elgas is your one-stop shop for all LPG supply and delivery, including 45kg cylinders popular for household use. Our service includes free delivery of replacement cylinders for an instant gas bottle refill. If LPG is on your wishlist for home appliance use or outdoor use, contact Elgas today for the best price products and services!

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Comments, questions or feedback?

Please Email us at:[emailprotected]

(Video) How to Fill a Gas Bottle - Fill Propane Tank - How to Refill LPG Gas Cylinder - Safely Decant LPG

The information in this article is derived from various sources and is believed to be correct at the time of publication.However, the information may not be error free and may not be applicable in all circumstances.


How big is a 9kg gas bottle? ›

A 9kg gas bottle is considered the standard-size BBQ gas bottle. 9kg represents the nominal weight of the gas contents. A 9kg gas bottle weighs approximately 17.5 kg when full, light enough to be portable for a wide range of purposes.

How much gas is in a 9kg bottle? ›

A 9kg gas bottle contains 17 litres or approximately 417 Megajoules of energy.

How long does 8.5 kg gas last? ›

Each burner is rated at 15MJ so that's 15×2=30MJ/hour of gas consumption. Then divide that into 417 (the number of MJ in the 8.5kg bottle) to get the running time: 417÷30=13.9 hours how long does a gas bottle last.

What is a 9kg gas bottle? ›

A 9kg gas bottle is considered the standard size BBQ gas bottle and is roughly equivalent to a 20 lb propane tank. LPG is called Propane in the United States, while Butane is also classified as liquified petroleum gas. 9kg represents the nominal weight of the gas contents.

What does a 9kg gas bottle weigh full? ›

A 9kg BBQ gas bottle, for example, can weigh around 16.3kg -19kg when full. The weight variation is in the empty 9kg gas bottle weight, as 9kg refers to the weight of the contents only.

Can I use a 9kg gas bottle on my house? ›

Can I hook up my bottle to my hob in the kitchen? Yep, internal installations are allowed. Up to 9Kg's in a flat, up to 19Kg's in a house.

Is 1kg equal to 1 liter? ›

How many liters of water is equal to 1 kg? 1 kilogram of pure water equals 1 liter when reaching its maximum density of 1 kg/l, at the temperature of 39.2 °F or 4 °C. For higher temperatures, 1 kg of water is slightly more than 1 liter.

How much is a 9kg gas bottle refill? ›

Want to order Gas? You can pay for 9 Kg Gas Bottle Refill online for only R296. 00.

How long will a 9kg gas bottle run a fridge? ›

If you now want to know how long a 9 kg gas cylinder will last, continue calculating. With consumption of 400 g gas per day, divide the total weight of the gas by the daily consumption: 9000 : 400 = 22.5. In other words, your 9 kg gas cylinder will last for about 22 days.

How long does a 9kg gas canister last? ›

This converts into 0.555 kg/h of lpg consumption. Therefore a 9 kg bottle would last 16 hours of continuous usage with all burners operating. For the average home a 9 kg will last 1-3 months for cooking.

Do gas bottles go out of date? ›

Do not use a cylinder that is out of date—the test date, stamped on the base or neck of the cylinder, is valid for 10 years. If you're using the cylinder with a low-pressure gas device, use a regulator to control the pressure—ask your gas supplier or the manufacturer to explain how.

How long does a kg gas bottle last? ›

If you have a Calor gas propane 6kg bottle – and if you consider that 1kg of propane can give around 13.6 kWh of energy – you may be able to use a cooker for about 81.6 hours.

Does gas bottle size matter? ›

Which BBQ gas bottle do I need - what size? This depends largely on how many burners your gas barbeque has. If it has between one and three, a 5kg patio gas bottle is ideal. If you've got a larger barbeque with four burners or more, then it's recommended that you select a 13kg bottle.

How long will a 9kg gas bottle run a 3 way fridge? ›

In fact, your 3 way fridge freezer can run for approximately 2-3 weeks on a 9kg gas bottle before it needs refilling. So, you can still do a big shop and enjoy chilled food and drink in the most remote spots.

Does a 9kg gas bottle need a cage? ›

Do my gas cylinders need to be secured to a wall? Yes, cylinders over 9kg, need to be secured either with a chain, or in a cage. This prevents damage to the installation and injury to property and persons.

What size is a kg gas cylinder? ›

45 kg gas bottle height = 1250mm. 45 kg LPG cylinder diameter = 375mm. 45 kg LPG cylinder capacity = 88 litres.

How do I know if my 9kg gas bottle is empty? ›

Most gas cylinders have the empty weight stamped on the cylinder somewhere, often on the neck of the cylinder. Pick up your gas bottle and place it on your bathroom scale. If the weight on the scale is the same (or almost the same) as the empty weight, then you know it's practically empty and needs refilling.

What do the numbers mean on a gas bottle? ›

The longer number series is the cylinder's serial number which uniquely identifies it to the manufacturer and gas supplier. The last series of numbers tell you the month and year the cylinder was hydrostatically tested by the manufacturer (April of 1999, March of 2009, and February of 1019).

Which type of gas cylinder is the best? ›

For onsite industrial use, a simple Type 1 gas cylinder is usually the most appropriate and best value solution. In typical applications such as metal fabrication and welding, the cylinders do not need to be moved, so heavier weights are not a major consideration. Cost is usually the primary factor.

Which gas cylinder is best for home use? ›

Natural gas (methane) it the type of gas used in homes most frequently. In areas where natural gas is unavailable, LPG, CNG or Biogas are used. Natural gas is delivered via pipelines whilst LPG and CNG are delivered in cylinders or tanks.

What size gas bottle do I need for my house? ›

The 45 Kg Gas Bottle Makes Gas Accessible to Every Home.

The 45kg gas bottle remains the most common domestic LPG gas bottle-cylinder used in homes across Australia, mainly because of its manoeuvrable size and versatility, it can be used for heating, hot water and cooking.

Is 10 litres the same as 10 kg? ›

The density of water is 1000 kg/m^3 and 10kg would be 10 Liters.

What is difference between kg and liter? ›

Kilo (kilogram) is a unit of mass: 1 kilo = 2.205 lbs. Liter is a unit of volume: 1 liter = 33.814 oz. Was this article helpful?

Do you get a refund on gas bottles? ›

If you would like to return a gas bottle, please call your local Calor Centre who can arrange collection and arrange a refund. If you have your Cylinder Refill Agreement paperwork you will receive a 25-70% refund of the original CRA cost. To contact your local Calor Centre please find their details here.

What is the cost of an empty cylinder? ›

₹ 1,300/ Pcs.

Can you run a gas fridge while driving? ›

A: Travelling with the gas turned on is a big no-no. All caravan and gas appliance manufacturers advise you to turn the gas off while travelling for safety. This is more due to having a naked flame running on your van, and associated dangers with entering a service station, than any issues with the fridge itself.

How long can you store a full gas bottle? ›

indefinitely. LPG shelf life is unlimited. The only limiting factor is the gas bottle itself. Assuming it is taken care of and not allowed to rust, it could last 20 years or more.

What happens if you put too much gas in a fridge? ›

If the system is overcharged more than 10 percent, liquid can enter the suction line and get to the suction valves or crankcase. This will cause compressor damage and eventually failure.

How often should you replace a gas bottle? ›

Gas bottles need retesting. In Australia, LP gas bottles require testing every ten (10) years. Filling a damaged or out-of-date gas bottle is illegal and can be dangerous. Out-of-date gas bottles need retesting and must not be refilled untl re-stamped by an approved gas cylinder test station.

How often do gas cylinders need to be replaced? ›

It's dangerous and also illegal to fill out-of-date or damaged cylinders. These cylinders require LPG gas cylinder testing and re-stamping at an approved test station. A complete periodic overhaul of an LPG cylinder every 10 or 15 years can include: gas bottle expiry confirmation.

Is 3 year old gasoline still good? ›

Gasoline can last between three months and three years depending on the type of gas and if it is properly stored. It's important to note while all gas will naturally begin to degrade over time thanks to exposure to oxygen (also known as oxidation), all gas is not created equal.

Is 4 year old gas still good? ›

The Shelf Life of Fuel

Regular gasoline has a shelf life of three to six months, while diesel can last up to a year before it begins to degrade. On the other hand, organic-based Ethanol can lose its combustibility in just one to three months due to oxidation and evaporation.

Is 8 year old gas still good? ›

Degradation occurs from the get-go but most gas stays fresh for a month or two without issue. However, gas that is more than two month old is generally OK to use with only minor decreases in performance. Gas that is older than a year can cause issues, like engine knocking, sputtering and clogged injectors.

Which is safer butane or propane? ›

At the end of the day, both gases emit no long-term negative effects on the environment. Propane and butane are both safe, non-toxic, clean burning fuels that are a great source of energy.

Can propane go bad? ›

Does propane expire? Another way you get peace of mind with propane delivery from Bottini Fuel is that propane doesn't have a shelf life or an expiration date. That's because propane doesn't go bad! Other fuel sources can degrade over time, like kerosene, diesel, heating oil and gasoline.

Should you empty a gas cylinder completely? ›

As with non-liquefied and dissolved gases, never empty the cylinder completely. Keep a small amount of material in the cylinder to maintain a slight positive pressure.

How much should a full gas bottle weigh? ›

A 9kg gas bottle is considered the standard-size BBQ gas bottle. 9kg represents the nominal weight of the gas contents. A 9kg gas bottle weighs approximately 17.5 kg when full, light enough to be portable for a wide range of purposes.

How much is 9kg gas refill? ›

Want to order Gas? You can pay for 9 Kg Gas Bottle Refill online for only R296. 00.

What does a full 9kg gas bottle weigh? ›

Domestic Gas Cylinder Weights Using a Scale

A 9kg gas bottle weighs approximately 16.3–19.0 kg when full.

Can you use a 9kg gas bottle on your house? ›

9kg LPG Gas Bottle Safety Issues

The following potential safety hazards will exist of you try to use a 9kg gas bottle in an LPG installation designed for a 45kg gas bottle: The 9kg gas bottle could end up hanging from its supply hose. The 9kg gas bottle is not secured and may fall.

Can you refill a 9kg gas bottle? ›

No. Gas cylinders are pressurised, and if you attempt to remove or refill that gas, you could suffer a potentially fatal accident.

How long does a 9kg gas bottle last? ›

This converts into 0.555 kg/h of lpg consumption. Therefore a 9 kg bottle would last 16 hours of continuous usage with all burners operating. For the average home a 9 kg will last 1-3 months for cooking.

How much kg is a full gas cylinder? ›

Your LPG delivery man carries a weighing scale. Always get your refill cylinder weighed in your presence before taking delivery. The weight of the empty cylinder (15.3*kg) is painted on its body (as shown in the picture.) Add the product weight (14.2**kg) to the empty cylinder weight to arrive at the gross weight.

What does the weight on a gas bottle mean? ›

All cylinders have a tare weight disk showing the weight of the cylinder, we then fill the bottle to the required amount the cylinder can hold. To check how much gas is remaining we would recommend using scales. For example the total weight of a 13kg cylinder is 25kg – the bottle weighs 12kg and the gas weighs 13kg.

What size is a standard house gas bottle? ›

45kg Gas Bottle Dimensions

45 kg LPG cylinder diameter = 375mm. 45 kg LPG cylinder capacity = 88 litres. 45kg gas bottle tare weight = 33 kg. 45 kg LPG cylinder full weight = 78 kg.

How much does it cost to fill up a 19kg gas cylinder? ›

Need help? Want to order Gas? You can pay for 19 Kg Gas Bottle Refill online for only R628. 00.

How long does a gas bottle last? ›

If LPG is used for cooking and hot water for a family of four, a 45kg gas bottle should last for a couple of months of clean-burning gas supply. If using LPG for cooking, Rinnai hot water and home heating, your gas cylinder should last for approximately one month.

Should I use all my gas before refilling? ›

Don't wait till the Tank is Empty

While filling your gas tank full is good, waiting to refill after it runs empty is bad. That damages the car's fuel pump because it will suck up the little remaining fuel at the tank base together with the dirt, debris, and particles.


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