Section 154.514 - Piping: Electrical bonding(a) Cargo tanks or piping that are separated from the hull structure by thermal isolation must be electrically bonded to the hull structure by a method under paragraph (c) of this section.(b) A pipe joint or a hose connection fitting that has a gasket must be electrically bonded by a method under paragraph (c) of this section that bonds: (1) Both sides of the connection to the hull structure; or(2) Each side of the connection to the other side.(c) An electrical bond must be made by at least one of the following methods:(1) A metal bonding strap attached by welding or bolting.(2) Two or more bolts that give metal to metal contact between the bolts and the parts to be bonded.(3) Metal to metal contact between adjacent parts under designed operating conditions.