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Product Description
Marine High-velocity Relief Valve DF-ISO-60 Type
The high-velocity relief valve ( pressure/vacuum valve for cargo oil tank ) has already been generally used by the relief system of the oil tanker and chemical tanker, according to the current regulations:IMO and IBC.
IS015364:standards of Ships and Marine Technology Pressure/Vacuum Valve for Cargo Tank and the publication of the IMO.MSC/Circ.1009 Circular provide standards for designing,manufacturing, experimenting and maintaining the high- velocity relief valve.
Basic structure of the DF high-velocity relief valve
The structure of DF-ISO-60 pressure vacuum valve is exactly the same as that of DF-ISO. Its opening pressure is set to 60.0kPa. It is mainly used for loading propylene oxide cargoes to ensure zero leakage of cargoes in the tank at 80% of the set pressure, and automatically release at a pressure above 80% to balance the tank pressure. This valve is a safety valve and is not used for loading operations. If it is equipped with a vacuum valve, it can be unloaded. Each liquid cargo tank should be equipped with one DF-ISO and one DF-ISO-60 pressure vacuum valve.
When the liquid cargo ships need to load the goods of the propylene oxide class , the ships have to be equipped with DF-IS0- 60 high- velocity relief valve.The valve manufacturing materials should be 304,304L,316L quality stainless steel, and the pressure valve opening pressure is generally set at 60kPa, vacuum valve and the DF type are equivalent.
Main Technical Parameters
| 表四Table 4 | |||||||||
| Model | Setting opening pressure (kPa) | Rated working pressure (kPa) | Flow rate (m³/h) | Pressure valve outlet diameter | MESG (mm) | connection pipe diameter (mm) | |||
| Pressure valve | Vacuum valve | pressure valve | Vacuum valve | Pressure valve | Vacuum valve | ||||
| DF-ISO-60 | ≤60.0 | -3.5~-7.0 | 60.0 | -7.0 | >600 | >600 | 50mm | ≥0.65 | DN80 DN100 DN125 |
Note: The design opening pressure of the pressure/vacuum valve required by the shipowner and the design institute is different. The pressure drop calculation of the ventilation system provided by the manufacturer shall determine the pressure and flow curve provided by the manufacturer when selecting the valve.
Note: (1) The above flow rate is standard air at 21'C (70'F), pressure 1013.25hpa, and density 1.29kg/m3; (2) The maximum pressure drop of the valve shall not exceed the design parameters of the cabin pressure.
