Pounds per square inch
The pound per square inch or, more accurately, pound-force per square inch (symbol: psi or lbf/in2 or lbf/in2 or lbf/sq in or lbf/sq in) is a unit of pressure or of stress based on avoirdupois units. It is the pressure resulting from a force of one pound-force applied to an area of one square inch:
1 psi approximately equals 6,894.757 Pa, where pascal (Pa) is the SI unit of pressure.
Magnitude
- Blood Pressure – Average human blood pressure (120/80): 2.32psi/1.55psi
- Boost Pressure Provided By an Automotive Turbocharger(common):Pg = 6–15psi
- Atmospheric pressure at sea level (standard): Pa = 14.7 psi
- Automobile tire overpressure (common): Pg = 32 psi
- Bicycle tire overpressure (common): Pg = 65 psi
- Workshop or garage air tools: Pg = 90 psi
- Air brake (rail) or Air brake (road vehicle) reservoir overpressure (common): 90 psi ≤ Pg ≤ 120 psi
- Road racing bicycle tire overpressure: Pg = 120 psi
- Steam locomotive fire tube boiler (UK, 20th century): 150 psi ≤ Pg ≤ 280 psi
- Union Pacific Big Boy steam locomotive boiler: 300 psi
- Natural gas pipelines: 800 to 1000 psi
- Full SCBA Self Contained Breathing Apparatus for toxic atmospheres: 2216 psi
- Full scuba tank overpressure (common): Pg = 3000 psi
- Commercial jet airliner hydraulic pressure: 3000 psi
- Airbus A380 hydraulic system: 5000 psi
- Water jet cutter: 40,000–100,000 psi
- Young's Modulus for steel: 30 Mpsi or 30,000,000 psi
Conversions
Pressure units
|
pascal |
bar |
technical atmosphere |
standard atmosphere |
torr |
pound per square inch |
| Pa |
bar |
at |
atm |
Torr |
psi |
| 1 Pa |
≡ 1 N/m2 |
10−5 |
1.0197×10−5 |
9.8692×10−6 |
7.5006×10−3 |
145.04×10−6 |
| 1 bar |
105 |
≡ 106 dyn/cm2 |
1.0197 |
0.98692 |
750.06 |
14.5037744 |
| 1 at |
0.980665 ×105 |
0.980665 |
≡ 1 kp/cm2 |
0.96784 |
735.56 |
14.223 |
| 1 atm |
1.01325 ×105 |
1.01325 |
1.0332 |
≡ p0 |
760 |
14.696 |
| 1 Torr |
133.322 |
1.3332×10−3 |
1.3595×10−3 |
1.3158×10−3 |
= 1 mmHg |
19.337×10−3 |
| 1 psi |
6.895×103 |
68.948×10−3 |
70.307×10−3 |
68.046×10−3 |
51.715 |
≡ 1 lbF/in2 |
See also
References
External links