Manhole Cover is an opening & closing devicewidely used in the ship cabin entrance.The ship is equipped with many tanks (such as fuel oil tank, oil tank, water tank, ballast tanks, etc.) and some for hull structure or pipe maintenance but usually no access to the cabin (such as the forepeak, tail tip tanks, cofferdams etc.). These cabins are under the freeboard deck or the middle platform, some in the double bottom, so we have to open the hole on the deck, bulkhead or platform floor of the closed cabin usually, and install the manhole cover as the access of the construction and maintenance personnel. As soon as the job is completed by personnel, the manhole cover is shut down. According to the goods feature in the tank, the manhole cover can be watertight or oiltight.According to the installment height, there are raised type, flush type, sunk type. Standard: CB/T19-2001 Shape: Round, Rectangular, Oval Certificate:CCS, ABS, BV, NK, DNV/GL,LR,IRS, RMRS,RINA