Psi To Psig Calculator

PSIG Formula:

\[ PSIG = PSI - 14.7 \]

PSIG (psig):

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1. What is PSI to PSIG Conversion?

PSI to PSIG conversion calculates gauge pressure from absolute pressure by subtracting atmospheric pressure (14.7 psi). PSIA (pounds per square inch absolute) includes atmospheric pressure, while PSIG (pounds per square inch gauge) measures pressure relative to atmospheric pressure.

2. How Does the Calculator Work?

The calculator uses the PSIG formula:

\[ PSIG = PSI - 14.7 \]

Where:

\( PSI \) — Absolute pressure in pounds per square inch (psia)
\( 14.7 \) — Standard atmospheric pressure at sea level (psi)
\( PSIG \) — Gauge pressure in pounds per square inch (psig)

Explanation: This conversion accounts for the atmospheric pressure that is always present, allowing measurement of pressure relative to ambient conditions.

3. Importance of PSI/PSIG Conversion

Details: Understanding the difference between absolute and gauge pressure is crucial in various engineering applications, including pneumatic systems, hydraulic systems, pressure vessel design, and industrial processes where accurate pressure measurement is essential for safety and performance.

4. Using the Calculator

Tips: Enter absolute pressure (PSIA) in pounds per square inch. The value must be greater than 0. The calculator will automatically subtract atmospheric pressure (14.7 psi) to provide the gauge pressure reading.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between PSI and PSIG?
A: PSI typically refers to absolute pressure (PSIA), while PSIG specifically denotes gauge pressure. PSIG = PSIA - atmospheric pressure.

Q2: Why is 14.7 psi used for atmospheric pressure?
A: 14.7 psi represents standard atmospheric pressure at sea level. This value may vary slightly with altitude and weather conditions.

Q3: When should I use PSIG vs PSIA?
A: Use PSIG for most pressure measurements (tire pressure, system pressure). Use PSIA for scientific calculations, vacuum measurements, and when absolute pressure is required.

Q4: Can PSIG be negative?
A: Yes, PSIG can be negative when measuring vacuum or pressures below atmospheric pressure.

Q5: How does altitude affect this conversion?
A: At higher altitudes, atmospheric pressure decreases, so the conversion factor would be less than 14.7 psi.