1. What is PSI to PSIG Conversion?

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

Purpose: It helps engineers, technicians, and mechanics work with pressure measurements in various systems.

2. How Does the Conversion Work?

The conversion 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 PSI/PSIG Conversion

Details: Proper pressure measurement is critical in HVAC systems, pneumatic tools, hydraulic systems, and industrial processes.

4. Using the Calculator

Tips: Enter the absolute pressure in PSI. The calculator will subtract standard atmospheric pressure (14.7 psi) to give you gauge pressure.

5. Frequently Asked Questions (FAQ)

Q1: Why subtract 14.7 psi?
A: This accounts for standard atmospheric pressure at sea level, converting absolute to gauge pressure.

Q2: When would PSIG be negative?
A: When absolute pressure is less than 14.7 psi, indicating a vacuum or pressure below atmospheric.

Q3: Does atmospheric pressure change?
A: Yes, with altitude and weather. For precise work at high elevations, use local atmospheric pressure.

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

Q5: Where is this conversion most used?
A: In tire pressure measurements, boiler systems, compressed air systems, and any application using pressure gauges.