The maximum suction distance of the self-priming pump is 10.13 meters.
A standard atmospheric pressure is 1.013×10^5 Pascal, which corresponds to the pressure at a height of 10.13 meters of water column.
No matter how good the self-priming pump is, under 1 standard atmospheric pressure, there is a vacuum in the upper pipe of 10.13 meters.
Thus, at 1 standard atmospheric pressure, the maximum suction distance of a self-priming pump is 10.13 meters.
Standard atmospheric pressure can only support a column of water 35 feet high.
P=ρgh (ρ density of the liquid, h height of the liquid, g≈10 Newton/kg)
101300=1000×10×h, the solution is h=10, 13 (meter)
Detailed information:
Standard temperature and pressure (STP ) were formerly defined in chemistry are 0°C (273.15K) and 101.325kPa (1atm), but from 1982 IUPAC hasredefined “standard pressure” to 100 kPa. 1 standard atmospheric pressure = 760 mm of mercury = 76 cm of mercury = 1.01325 × 10^5 Pa = 10.339 m of water column. 1 standard atmospheric pressure = 101325 N/m?. (In calculations, this is usually 1 standard atmosphere = 1.01×10^5 N/㎡). 100 kPa = 0.1 MPa.
The Earth is surrounded by thick air, called the atmosphere. Air can flow as freely as water, but it is also affected by gravity. So there is pressure inside the air in all directions. This pressure is called atmospheric pressure.
Italian scientist Torricelli filled a thin glass tube 80 centimeters long with mercury and placed it upside down in a sink containing mercury. He found that the mercury in the glass tube dropped about 4 centimeters and then stopped. . Fall again. No air penetrates this 4 cm space, it is a vacuum. Torricelli concludes that the pressureon of the atmosphere is equal to the length of the column of mercury. According to the pressure formula, scientists have accurately calculated that the atmospheric pressure under standard conditions is 1.01×10^5Pa.
Atmospheric pressure is not fixed. In order to compare the magnitude of atmospheric pressure, at the 10th International Conference on Weights and Measures in 1954, scientists established a "standard" for atmospheric pressure: at sea level at 45° latitude, when the temperature is 0°C, the pressure generated by a column of mercury 760 mm high. The pressure is called standard atmospheric pressure.
As this is a “standard”, we must pay attention to the correctness of the values of each physical quantity when calculating according to the liquid pressure formula. From relevant information, it can be found that the density of mercury at 0℃ is 13.595×10^3 kg/m? and that the value G at level de sea at 45° latitude is 9.80672 N/kg. Therefore, the pressure generated by a column of mercury 760 mm high is
pmercury=ρmercurygh=13.595×10^3kg/m?×9.80672N/Kilogram × 0.76 meter = 1.01325 × 10^5 Pa.
This is the value of a standard atmosphere.
Baidu Encyclopedia - Standard Atmospheric Pressure