Automatic closing system by disk float, and applicable to ballast tanks or oil tanks, etc. Main body is made of grey iron casting (FC-200). Connection flanges specifications are based on JIS 5 kgf/cm2. Application of IACS (International Association of Classification Societies) unified requirements P3 (1991), and approved by NK, ABS, LRS, DNV and BV. Please specify the flange size to be connected with type of pipe head when ordering. Model: 53B Ⅱ