Look for the latest date stamped on the valve protection guard / handle, whether it is the original manufacture date, or a requalifying date.  If today's date is less than ten years from that one, you don't need to requalify it. It doesn't need to be recertified. If the date is longer than ten years, bring it in and we can inspect it and recertify it, if it qualifies. If you are unsure, bring it in and we'll look at it for you.