All the joints in spirit pipes must either be riveted or be joined with bolts. In the latter case, the flanges bolted together must have in addition to the bolts, at least two rivets made of a composition of lead or tin, and sealed with a revenue seal, or, in the case of certain joints when this is specially permitted by the Financial Commissioner the flanges may be pierced by a bolt carrying a revenue lock, inserted through a hole, at one end of the bolt. Alternately the flanges may be drilled with a hole 3.75 millimetres (⅛ th of an inch) in diameter through which a wire should be twisted together and sealed with a revenue seal.
