Pressure
Convert pound per square inch (psi) to standard atmosphere (atm). Pressure is force per unit area. Process engineers move constantly between SI (kPa, bar) and US (psi) units, and between absolute and gauge.
1 psi = 0.06804596 atm
To convert pound per square inch to standard atmosphere, multiply the psi value by 0.06804596. To go the other way, divide by 0.06804596 (or multiply by 14.69595).
| psi | atm |
|---|---|
| 1 | 0.06804596 |
| 2 | 0.1360919 |
| 5 | 0.3402298 |
| 10 | 0.6804596 |
| 25 | 1.701149 |
| 50 | 3.402298 |
| 100 | 6.804596 |
| 250 | 17.01149 |
| 500 | 34.02298 |
| 1000 | 68.04596 |
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 145.0377 psi is 9.869233 atm.
Multiply the value in psi by 0.06804596 to get atm. For example, 10 psi = 0.6804596 atm.
1 psi equals 0.06804596 atm.
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.