Keywords:
Circular shape, Classification, Classification systems, Classifications, Closures, Design, Designations, Dimensions, Duty series, Elongation at fracture, Fixings, Frames, Heavy, Hinges, Interchangeable, Light (magnitude), Main frames, Marking, Materials, Materials specification, Medium loading, Mounting, Offshore engineering, Panes (windows), Portholes, Punching tests, Shipbuilding, Ship's equipment, Side scuttles, Specifications, Tensile strength, Testing, Toughened safety glass, Waterproofness, Windows