Some places will take it in exchange for getting a tank full of propane. Your best bet is to sell it online
There is also a month and year on the collar indicating the date the tank was made. For 20 lb propane tanks, you have 12 years from the manufacture date before the tank must be re-certified with a new date stamped on it. The re-certification only adds 5 years before having to re-certify again. We do tank exchange tanks & we also refill tanks by the gallon.
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