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2022

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How to convert PSI and MPa pressure units?

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Psi and MPa conversion, psi is the pressure unit, defined as pounds per square inch, 145psi=1MPa , PSI is called Poundspersquareinch in English . P is pound , S is square , and I is inches . Convert all units to metric units and you can calculate: 1bar ≈ 14.5psi, 1psi=6.895kPa=0.06895bar European and American countries are accustomed to using psi as the unit .

Psi and MPa conversion, psi is the pressure unit, defined as pounds per square inch, 145psi=1MPa , PSI is called Poundspersquareinch in English . P is pound , S is square , and I is inches . Convert all units to metric units and you can calculate: 1bar 14.5psi, 1psi=6.895kPa=0.06895bar European and American countries are accustomed to using psi as the unit .

     In China, we generally describe the pressure of gases as "kg" (instead of "jin"), and the unit of volume is "kg/cm^2". One kilogram of pressure means one kilogram of force acting on one square centimeter.

     The commonly used unit abroad is "Psi", and the specific unit is "lb/in2", which is "pounds per square inch". This unit is like the Fahrenheit temperature scale (F).

     In addition, there are pressure units such as Pa (Pascal, one Newton acts on one square meter), KPa, MPa, Bar, millimeters of water column, millimeters of mercury, etc.

 

 1 bar (bar) = 0.1 MPa (MPa) = 100 kilopascal (KPa) = 1.0197 kg/cm2

 1 standard atmospheric pressure (ATM) = 0.101325 MPa (MPa) = 1.0333 bar (bar)

Because the unit difference is very small, it can be written like this:

     1 bar (bar) = 1 standard atmosphere (ATM) = 1 kg/cm2 = 100 kilopascal (KPa) = 0.1 megapascal (MPa)

The conversion of psi is as follows:

     1 standard atmosphere (atm) = 14.696 pounds/inch2 (psi)

 

Pressure conversion relationship:

    Pressure 1 bar (bar) = 10^5 Pa (Pa) 1 dyn/cm2 (dyn/cm2) = 0.1 Pa (Pa)

    1 Torr (Torr) = 133.322 Pascal (Pa) 1 millimeter of mercury (mmHg) = 133.322 Pascal (Pa)

    1 millimeter of water column (mmH2O) = 9.80665 Pa (Pa)

    1 Engineering atmospheric pressure = 98.0665 kPa (kPa)

    1 kPa (kPa) = 0.145 pounds force/inch2 (psi) = 0.0102 kilogram force/cm2 (kgf/cm2) = 0.0098 atmospheric pressure (atm)

    1 pound force/inch2 (psi)=6.895 kilopascal (kPa)=0.0703 kilogram force/cm2 (kg/cm2)=0.0689 bar (bar)=0.068 atmospheric pressure (atm)

    1 Physical atmospheric pressure (atm) = 101.325 kilopascal (kPa) = 14.696 pounds/inch2 (psi) = 1.0333 bar (bar)

     There are two types of valve systems: one is the "nominal pressure" system represented by Germany (including my country), which is based on the allowable working pressure at normal temperature (100 degrees in my country and 120 degrees in Germany). One is the "temperature pressure system" represented by the United States, which is represented by the allowable working pressure at a certain temperature.

     In the American temperature and pressure system, except for 150LB which is based on 260 degrees, all other levels are based on 454 degrees.

    The allowable stress of a 150-pound grade (150psi=1MPa) No. 25 carbon steel valve at 260 degrees is 1MPa, while the allowable stress at normal temperature is much greater than 1MPa, about 2.0MPa.

     Therefore, generally speaking, the nominal pressure level corresponding to the American standard 150LB is 2.0MPa, the nominal pressure level corresponding to the 300LB is 5.0MPa, and so on.

     Therefore, the nominal pressure and temperature and pressure levels cannot be converted casually according to the pressure conversion formula.

 

Psi to MPa pressure conversion table