Psi is converted to MPa, where psi is the unit of pressure, defined as pounds per square inch, with 145psi=1MPa. PSI is also known as Poundspersquare inch in English. P is pound pound, S is square, and I is inch. By replacing all units with metric units, it can be calculated that 1 bar ≈ 14.5 psi, 1 psi=6.895 kPa=0.06895 bar. European and American countries commonly use psi as the unit
In China, we generally describe the pressure of a gas as "kilogram" (rather than "jin"), with the unit of volume being "kg/cm ^ 2". One kilogram of pressure is the force of one kilogram acting on one square centimeter.
The commonly used unit in foreign countries is "Psi", specifically "lb/in2", which is "pounds per square inch", similar to the Fahrenheit temperature scale (F).
In addition, there are pressure units such as Pa (Pascal, one Newton acting on one square meter), KPa, Mpa, Bar, millimeter water column, and millimeter mercury column.
1 bar=0.1 MPa=100 kPa=1.0197 kg/cm2
1 standard atmospheric pressure (ATM)=0.101325 MPa=1.0333 bar
Because the difference in units is very small, it can be written as follows:
1 bar=1 standard atmospheric pressure (ATM)=1 kilogram/square centimeter=100 kPa=0.1 MPa
The conversion of psi is as follows:
1 standard atmospheric pressure (atm)=14.696 pounds per inch 2 (psi)
Pressure conversion relationship:
Pressure 1 bar=10 ^ 5 Pa 1 dyne/cm2=0.1 Pa
1 Torr=133.322 Pa 1 mmHg=133.322 Pa
1 millimeter water column (mmH2O)=9.80665 Pa
1. Engineering atmospheric pressure=98.0665 kPa
1 kPa=0.145 lbf/inch2 (psi)=0.0102 kgf/cm2 (kgf/cm2)=0.0098 atmospheric pressure (atm)
1 lbf/inch2 (psi)=6.895 kPa=0.0703 kgf/cm2 (kg/cm2)=0.0689 bar (bar)=0.068 atmospheric pressure (atm)
1 Physical atmospheric pressure (atm)=101.325 kPa=14.696 pounds per inch 2 psi=1.0333 bar
There are two types of valve systems: one is the "nominal pressure" system represented by Germany (including China), which is based on the allowable working pressure at room temperature (100 degrees in China and 120 degrees in Germany). One is the "temperature pressure system" represented by the United States, represented by the allowable working pressure at a certain temperature
In the temperature and pressure system of the United States, except for 150LB, which is based on 260 degrees, all other levels are based on 454 degrees.
The allowable stress of the No. 25 carbon steel valve in the 150 pound class (150psi=1MPa) is 1MPa at 260 degrees Celsius, and the allowable stress at room temperature is much greater than 1MPa, approximately 2.0MPa.
So, generally speaking, the nominal pressure level corresponding to the American standard 150LB is 2.0MPa, and the nominal pressure level corresponding to the 300LB is 5.0MPa, etc.
Therefore, the nominal pressure and temperature pressure level cannot be changed arbitrarily according to the pressure transformation formula