1. What is PSI to PSIG Conversion?

Definition: This calculator converts absolute pressure (PSI) to gauge pressure (PSIG) by subtracting atmospheric pressure (14.7 psi).

Purpose: It helps engineers, technicians, and professionals working with pressure systems to convert between absolute and gauge pressure measurements.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( PSIG \) — Gauge pressure (pounds per square inch gauge)
• \( PSI \) — Absolute pressure (pounds per square inch absolute)
• \( 14.7 \) — Standard atmospheric pressure at sea level (psi)

Explanation: Gauge pressure represents pressure relative to atmospheric pressure, while absolute pressure includes atmospheric pressure.

3. Importance of Pressure Conversion

Details: Proper pressure conversion ensures accurate measurements in various applications like HVAC systems, industrial processes, and pneumatic controls.

4. Using the Calculator

Tips: Enter the absolute pressure in PSI (must be > 0). The calculator will automatically subtract atmospheric pressure (14.7 psi) to give the gauge pressure.

5. Frequently Asked Questions (FAQ)

Q1: Why subtract 14.7 psi?
A: 14.7 psi is standard atmospheric pressure at sea level. Gauge pressure measures pressure above atmospheric.

Q2: What if I'm at high altitude?
A: Atmospheric pressure decreases with altitude. You may need to adjust the 14.7 value for precise calculations at high elevations.

Q3: Can PSIG be negative?
A: Yes, negative PSIG indicates vacuum (pressure below atmospheric).

Q4: What's the difference between PSI and PSIG?
A: PSI is absolute pressure (including atmospheric), while PSIG is relative to atmospheric pressure.

Q5: When would I use absolute vs gauge pressure?
A: Use absolute for scientific calculations, gauge for most industrial applications where atmospheric pressure is the reference.