If you have a torch that mixes fuel gas and oxygen in the torch you must have a flashback arrestor, not just a simple check valve.
If you are using a torch with a small opening at the tip and you get a piece of metal that blocks gas flow the higher pressure of your oxygen will push back on the lower pressure of the fuel gas and start to flow toward the fuel source. If you have a spark in there you have all the elements of fire…oxygen, fuel and heat. The flashback will travel to the fuel source where it will explode.
Jewelers explode their gas meters when they use natural gas without flashback arrestors. The only difference is you have a small tank of gas instead of a gas meter, but the effect will be the same. You can learn more about flashback arrestors and torch safety on our website here: http://www.safe-t-gas.com/NYCJewelers.html#FlashbackArrestorCheckValve
This web page is specifically for New York City jewelers, but the impact is the same for anyone using a torch with fuel and oxygen.
Ed Howard
G-TEC Natural Gas Systems
ehoward@gas-tec.com
www.safe-t-gas.com