Abstract: A closure can close an outlet of a vessel. The vessel outlet can comprise a tubular cavity with an interior surface. The closure can comprise a male portion comprising a distal undersized portion, a proximal oversized portion, and a taper between the undersized and oversized portion. The male portion can be inserted in the vessel outlet, undersized portion first. Interference between the inner diameter of the vessel outlet and the outer diameter of male portion can occur when the male portion is sufficiently inserted. The interference can cause the undersized portion to flare out and engage the interior surface of the tubular cavity, thereby providing a seal.

Abstract: A closure can close an outlet of a vessel. The vessel outlet can comprise a tubular cavity with an interior surface. The closure can comprise a male portion comprising a distal undersized portion, a proximal oversized portion, and a taper between the undersized and oversized portion. The male portion can be inserted in the vessel outlet, undersized portion first, to close the vessel. A releasable catch can facilitate closing and opening the vessel repeatedly. A pull ring can support opening the vessel or closing the vessel or toting the vessel or any combination of opening, closing, and toting the vessel. The pull ring can have one or more associated hinges.

Abstract: A closure can close an outlet of a vessel. The vessel outlet can comprise a tubular cavity with an interior surface. The closure can comprise a male portion comprising a distal undersized portion, a proximal oversized portion, and a taper between the undersized and oversized portion. The male portion can be inserted in the vessel outlet, undersized portion first. Interference between the inner diameter of the vessel outlet and the outer diameter of male portion can occur when the male portion is sufficiently inserted. The interference can cause the undersized portion to flare out and engage the interior surface of the tubular cavity, thereby providing a seal.