There is a large number of saturation vapor pressure equations used to calculate the pressure of water vapor over a surface of liquid water or ice. This is a brief overview of the most important equations used. Several useful reviews of the existing vapor pressure curves are listed in the references. Please note the updated discussion of the WMO formulation. 1) Vapor Pressure over liquid water
20号钢 mm Mpa Mpa mm mm ℃ DN DO(外径) 许用应力 P(设计压力) t( 壁厚) 实际内径 温度 许用应力 15 22 130 7 3.216923 15.56615 20 130 20 27 130 7 3.370769 20.25846 100 130 25 34 130 7 3.586154 26.82769 150 130 40 48 130 7 4.016923 39.96615 200 123 50 60 90 6 4.825714 50.34857 250 110 80 89 130 7 5.278462 78.44308 300 101 100 114 130 7 6.047692 101.9046 350 92 150 168 130 7 7.709231 152.5815 400 86 200 230 130 7 9.616923 210.76