Pressure
Convert kilopascal (kPa) 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 kPa = 4.014631 inH₂O
To convert kilopascal to inch of water column, multiply the kPa value by 4.014631. To go the other way, divide by 4.014631 (or multiply by 0.2490889).
| kPa | inH₂O |
|---|---|
| 1 | 4.014631 |
| 2 | 8.029262 |
| 5 | 20.07315 |
| 10 | 40.14631 |
| 25 | 100.3658 |
| 50 | 200.7315 |
| 100 | 401.4631 |
| 250 | 1003.658 |
| 500 | 2007.315 |
| 1000 | 4014.631 |
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 1000 kPa is 4014.631 inH₂O.
Multiply the value in kPa by 4.014631 to get inH₂O. For example, 10 kPa = 40.14631 inH₂O.
1 kPa equals 4.014631 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.