Pressure
Convert pascal (Pa) to inch of water column (inH₂O). Pressure is force per unit area. Process engineers move constantly between SI (kPa, bar) and US (psi) units, and between absolute and gauge.
1 Pa = 0.004014631 inH₂O
To convert pascal to inch of water column, multiply the Pa value by 0.004014631. To go the other way, divide by 0.004014631 (or multiply by 249.0889).
| Pa | inH₂O |
|---|---|
| 1 | 0.004014631 |
| 2 | 0.008029262 |
| 5 | 0.02007315 |
| 10 | 0.04014631 |
| 25 | 0.1003658 |
| 50 | 0.2007315 |
| 100 | 0.4014631 |
| 250 | 1.003658 |
| 500 | 2.007315 |
| 1000 | 4.014631 |
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 1000000 Pa is 4014.631 inH₂O.
Multiply the value in Pa by 0.004014631 to get inH₂O. For example, 10 Pa = 0.04014631 inH₂O.
1 Pa equals 0.004014631 inH₂O.
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.