Pressure conversions: 1) What is the absolute pressure in psia equivalent to 150 psig? 2) What is the gauge pressure equivalent to 90 psia? 3) What is the equivalent of 75.2 psi when reported in kPa? 4) What is the equivalent of 15.0 in Hg when reported in psi?
The Correct Answer and Explanation is:
Here are the correct answers:
- Absolute pressure equivalent to 150 psig:
164.7 psia - Gauge pressure equivalent to 90 psia:
75.3 psig - 75.2 psi in kilopascals:
518.5 kPa - 15.0 inches of mercury in psi:
7.35 psi
Explanation
Pressure can be measured in different ways, mainly gauge pressure and absolute pressure. Gauge pressure (psig) measures pressure relative to the local atmospheric pressure. Absolute pressure (psia) includes atmospheric pressure in its measurement. At sea level, atmospheric pressure is approximately 14.7 psi.
1) Converting 150 psig to psia:
To convert gauge pressure to absolute pressure, you add atmospheric pressure: psia=psig+atmospheric pressure\text{psia} = \text{psig} + \text{atmospheric pressure}psia=psig+atmospheric pressure psia=150+14.7=164.7 psia\text{psia} = 150 + 14.7 = 164.7 \text{ psia}psia=150+14.7=164.7 psia
2) Converting 90 psia to psig:
To convert absolute pressure to gauge pressure, subtract atmospheric pressure: psig=psia−atmospheric pressure\text{psig} = \text{psia} – \text{atmospheric pressure}psig=psia−atmospheric pressure psig=90−14.7=75.3 psig\text{psig} = 90 – 14.7 = 75.3 \text{ psig}psig=90−14.7=75.3 psig
3) Converting 75.2 psi to kPa:
To convert psi to kilopascals (kPa), use the conversion factor:
1 psi = 6.89476 kPa 75.2×6.89476=518.5 kPa75.2 \times 6.89476 = 518.5 \text{ kPa}75.2×6.89476=518.5 kPa
4) Converting 15.0 in Hg to psi:
To convert inches of mercury (in Hg) to psi, use the conversion:
1 in Hg = 0.491154 psi 15.0×0.491154=7.36731≈7.35 psi15.0 \times 0.491154 = 7.36731 \approx 7.35 \text{ psi}15.0×0.491154=7.36731≈7.35 psi
Understanding how to convert between these units is important in physics, engineering, and meteorology. These conversions help ensure that measurements taken in one system are accurately interpreted in another. Always be careful to distinguish between absolute and gauge pressures, especially in technical applications.
