#230-110: Stamp, Plus Symbol “+” 1/4″ Char.

Required to be stamped on a cylinder where 10% overfill is allowed.

Plus stamping should only be done by those that are familiar with 49CFR section 173.302(c) and the CGA C-5 pamphlet. For those licensed in the US and Canada your license application must show that you are plus stamping cylinders.