Pressure Conversion Guide
Pressure is force per unit area, fundamental to fluid mechanics, thermodynamics, and structural analysis. The SI unit is the pascal (Pa), where 1 Pa = 1 N/m². Because 1 Pa is very small, kPa, MPa, and bar are more practical.
Key conversions: 1 atm = 101.325 kPa = 14.696 psi = 760 mmHg = 1.01325 bar, 1 bar = 100 kPa, 1 MPa = 145.038 psi, 1 psi = 6.89476 kPa.
Pressure measurement is critical in process engineering (vessel design per ASME codes), HVAC (duct static pressure), hydraulics (system operating pressure), meteorology, and medical devices (blood pressure in mmHg).
The most dangerous pitfall is confusing gauge and absolute pressure. Gauge pressure reads zero at atmospheric pressure, while absolute pressure reads zero at perfect vacuum. At sea level, P_abs = P_gauge + 14.696 psi. Misreading psig as psia can cause ~15% overpressure in vessel design, potentially leading to catastrophic failure.