Pressure
Convert standard atmosphere (atm) to pound per square inch (psi). Pressure is force per unit area. Process engineers move constantly between SI (kPa, bar) and US (psi) units, and between absolute and gauge.
1 atm = 14.69595 psi
To convert standard atmosphere to pound per square inch, multiply the atm value by 14.69595. To go the other way, divide by 14.69595 (or multiply by 0.06804596).
| atm | psi |
|---|---|
| 1 | 14.69595 |
| 2 | 29.3919 |
| 5 | 73.47975 |
| 10 | 146.9595 |
| 25 | 367.3987 |
| 50 | 734.7975 |
| 100 | 1469.595 |
| 250 | 3673.987 |
| 500 | 7347.975 |
| 1000 | 14695.95 |
Line and vessel ratings, pump discharge heads, and relief set points are all specified in pressure units — usually psi or barg in the field and kPa in calculations.
Always track whether a value is absolute or gauge: 0 barg equals about 101.3 kPa absolute, and mixing the two is a common and costly error.
Worked example. A pressure of 9.869233 atm is 145.0377 psi.
Multiply the value in atm by 14.69595 to get psi. For example, 10 atm = 146.9595 psi.
1 atm equals 14.69595 psi.
Line and vessel ratings, pump discharge heads, and relief set points are all specified in pressure units — usually psi or barg in the field and kPa in calculations.