kPa to PSI Converter

Converting metric pressure (kPa) to US customary (psi) for instrument calibration, equipment specification, and international process documentation.

HVAC service technicians in the US use manifold gauges in psig for refrigerant pressure, while the same equipment when sold in Europe reads in bar (or sometimes kPa for low-pressure systems) — converting between these readings is essential for charging refrigerant and verifying superheat/subcooling, with the conversion factor 1 psig ≈ 6.895 kPa.

Differential pressure transmitters in HVAC (for filter status, duct static pressure, building pressure) and process applications (for flow measurement with orifice plates, level measurement with dp cells) are configurable for either unit system, and the HART, Foundation Fieldbus, or PROFIBUS configuration must be in the local unit — a filter ΔP switch set to trip at 0.5 in w.c.

(about 0.024 psi = 0.166 kPa) is the same as setting it to 0.166 kPa.

Pneumatic test pressures for piping, vessels, and equipment are commonly in kPa in international EPC projects and psi in US-domestic projects — a hydrostatic test at 1.5× design pressure of 1,000 kPa would be 1,500 kPa test, equal to 217.6 psi.

Boiler and pressure vessel code calculations per ASME (US, psi) and PD 5500 / EN 13445 (Europe, bar) require consistent unit tracking through the calculation, with the conversion 1 psi = 6.895 kPa (or 1 bar = 14.504 psi) applied at every data entry point.

Cleanroom and pharmaceutical isolator pressure differentials per FDA, EMA, and WHO guidelines are typically specified in Pa (often 10–15 Pa between rooms of different cleanliness classes) and require conversion to psi for US-side documentation (1 Pa = 0.000145 psi, so 15 Pa = 0.00218 psi, a very small differential that requires sensitive magneto-resistive or thermal transmitters to measure accurately).

Compressed air system pressure ratings for shop air are 100 psi (6.9 bar, 690 kPa) in the US and 6–8 bar (600–800 kPa) in Europe, with the conversion applied when integrating equipment from different regions.

Fire protection system pressures per NFPA 13 (US, psi) and EN 12845 (Europe, bar or kPa) require conversion when designing or approving international projects.

Medical device and pharmaceutical process equipment (sterilizers, autoclaves, washer-disinfectors, lyophilizers) is specified with both psi (US) and kPa (international) ratings on the nameplate, and operators must be able to read the setpoint in their local unit system.

Hydraulic hose and fitting working pressures are typically in psi (US) and bar (Europe) — a 3000-psi hydraulic hose equals about 207 bar (20,700 kPa), and stocking the correct hose requires matching the regional system pressure convention.