PT chart · ASHRAE A1
R-12 PT Chart
R-12 pressure–temperature chart in psig and °F/°C. Older refrigeration and vehicle AC (phased out).
Vacuum readings are shown in inches of mercury (″ Hg) below atmospheric pressure.
| °F | °C | Pressure, psig |
|---|---|---|
| -50 | -45.6 | 15.4″ Hg |
| -45 | -42.8 | 13.3″ Hg |
| -40 | -40.0 | 11.0″ Hg |
| -35 | -37.2 | 8.4″ Hg |
| -30 | -34.4 | 5.5″ Hg |
| -25 | -31.7 | 2.4″ Hg |
| -20 | -28.9 | 0.5 |
| -15 | -26.1 | 2.4 |
| -10 | -23.3 | 4.5 |
| -5 | -20.6 | 6.7 |
| 0 | -17.8 | 9.1 |
| 5 | -15.0 | 11.7 |
| 10 | -12.2 | 14.6 |
| 15 | -9.4 | 17.7 |
| 20 | -6.7 | 21.0 |
| 25 | -3.9 | 24.6 |
| 30 | -1.1 | 28.4 |
| 35 | 1.7 | 32.5 |
| 40 | 4.4 | 36.9 |
| 45 | 7.2 | 41.6 |
| 50 | 10.0 | 46.6 |
| 55 | 12.8 | 51.9 |
| 60 | 15.6 | 57.6 |
| 65 | 18.3 | 63.7 |
| 70 | 21.1 | 70.1 |
| 75 | 23.9 | 76.8 |
| 80 | 26.7 | 84.0 |
| 85 | 29.4 | 91.6 |
| 90 | 32.2 | 99.6 |
| 95 | 35.0 | 108.0 |
| 100 | 37.8 | 116.9 |
| 105 | 40.6 | 126.3 |
| 110 | 43.3 | 136.1 |
| 115 | 46.1 | 146.4 |
| 120 | 48.9 | 157.3 |
| 125 | 51.7 | 168.6 |
| 130 | 54.4 | 180.5 |
| 135 | 57.2 | 193.0 |
| 140 | 60.0 | 206.0 |
| 145 | 62.8 | 219.7 |
| 150 | 65.6 | 233.9 |
Source: NIST Chemistry WebBook, SRD 69, saturation properties. Converted from absolute pressure (psia) to psig. Reference only; verify against the equipment manufacturer's data.
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