I had heard that the number stamped on the gas bottle actually means something. I never really worried about it. I was even going to buy a cheap spare bottle. I had read that I need a No2 bottle for Caravan use and all the cheapies are 4's, just good for the back yard. Anyway I thought this info' might be helpful.
Quote: "In Australian Standard AS 2469 - 2005, the categories which are stamped (numbers 1 to 4) in a circle on the top of the cowall surrounding the valve assembly on gas bottles are as follows:
1 Hot Dip Galvanizing
2 Abrasive blasted + inorganic zinc rich coating + organic zinc rich coating.
3 Sprayed Zinc Coating
4 Red oxide or polyester powder coat.
The numbers refer to the rust proofing treatment of the steel, not the thickness of the steel. Obviously, the thickness of the treatment will vary eg hot dip galvanising is thicker than powder coating. So, when exchanging gas bottles, the number 1 in the circle should be preferred. The number 2 bottles should be the minimal treatment for caravan usage. The number 3 and the powder coated type with number 4 in the circle should be restricted to home use.
Each gas bottle is date stamped for a period of ten years, and cannot be filled outside of that date without being refurbished and inspected and stmaped for a further ten year period, regardless of the amount of use it has had."
Source: http://www.australiasomuchtosee.com/gas.htm
On the weekend before going away, I realized we needed a bottle. I did not want to change my Jayco/Manchester bottle, so I took down a crappy one I had to the servo. Hunted around and found 2,3 & plenty of 4's. I looked for a Manchester brand so it would fit the holder, tip I learnt was the washer on top of the valve says Manchester, saves pulling them out. Anyway I found one exactly the same as Jayco use, so it fitted perfectly and it was a No2. Bonus I have a good spare they are not getting back!
Anyway I dont know if the info is current but it seems to make sense.

Cheers Geoff
Quote: "In Australian Standard AS 2469 - 2005, the categories which are stamped (numbers 1 to 4) in a circle on the top of the cowall surrounding the valve assembly on gas bottles are as follows:
1 Hot Dip Galvanizing
2 Abrasive blasted + inorganic zinc rich coating + organic zinc rich coating.
3 Sprayed Zinc Coating
4 Red oxide or polyester powder coat.
The numbers refer to the rust proofing treatment of the steel, not the thickness of the steel. Obviously, the thickness of the treatment will vary eg hot dip galvanising is thicker than powder coating. So, when exchanging gas bottles, the number 1 in the circle should be preferred. The number 2 bottles should be the minimal treatment for caravan usage. The number 3 and the powder coated type with number 4 in the circle should be restricted to home use.
Each gas bottle is date stamped for a period of ten years, and cannot be filled outside of that date without being refurbished and inspected and stmaped for a further ten year period, regardless of the amount of use it has had."
Source: http://www.australiasomuchtosee.com/gas.htm
On the weekend before going away, I realized we needed a bottle. I did not want to change my Jayco/Manchester bottle, so I took down a crappy one I had to the servo. Hunted around and found 2,3 & plenty of 4's. I looked for a Manchester brand so it would fit the holder, tip I learnt was the washer on top of the valve says Manchester, saves pulling them out. Anyway I found one exactly the same as Jayco use, so it fitted perfectly and it was a No2. Bonus I have a good spare they are not getting back!
Anyway I dont know if the info is current but it seems to make sense.

Cheers Geoff