R-507A PT Chart
A1 GWP 3985Azeotropic blend (R-125/R-143a). HFC Blend.
Phase-down (high GWP)
Boiling Point
-52.1°F
-46.7°C
Critical Temp
159.1°F
70.6°C
Critical Pressure
537.4 psia
37.05 bar
About R-507A
R-507A is an azeotropic 50/50 blend of R-125 and R-143a, used in the same low- and medium-temperature refrigeration applications as R-404A with nearly identical pressures. Because it is an azeotrope it has no glide, and it can be charged as vapor without changing composition.
Saturation pressures at typical operating points, taken from the table below:
- Freezer evaporator (−20°F): 17.6 PSIG
- Medium-temp evaporator (20°F): 58.3 PSIG
- Condensing (105°F): 260.1 PSIG
The table covers -80°F to 150°F in 5°F steps. Below about -52°F the saturation pressure is below atmospheric, so gauges read in vacuum (shown in blue in the table).
R-507A Pressure-Temperature Graph
R-507A Saturation Pressure Table
Blue values indicate vacuum (below atmospheric pressure).
| °F | °C | PSIG | PSIA | kPa | bar |
|---|---|---|---|---|---|
| -80 | -62.2 | -8.2 | 6.54 | 45.1 | 0.451 |
| -75 | -59.4 | -7.1 | 7.64 | 52.6 | 0.526 |
| -70 | -56.7 | -5.8 | 8.88 | 61.2 | 0.612 |
| -65 | -53.9 | -4.4 | 10.28 | 70.9 | 0.709 |
| -60 | -51.1 | -2.8 | 11.85 | 81.7 | 0.817 |
| -55 | -48.3 | -1.1 | 13.6 | 93.8 | 0.938 |
| -50 | -45.6 | 0.9 | 15.55 | 107.2 | 1.072 |
| -45 | -42.8 | 3.0 | 17.72 | 122.2 | 1.222 |
| -40 | -40.0 | 5.4 | 20.11 | 138.7 | 1.387 |
| -35 | -37.2 | 8.1 | 22.75 | 156.9 | 1.569 |
| -30 | -34.4 | 11.0 | 25.65 | 176.9 | 1.769 |
| -25 | -31.7 | 14.1 | 28.83 | 198.8 | 1.988 |
| -20 | -28.9 | 17.6 | 32.3 | 222.7 | 2.227 |
| -15 | -26.1 | 21.4 | 36.09 | 248.8 | 2.488 |
| -10 | -23.3 | 25.5 | 40.21 | 277.2 | 2.772 |
| -5 | -20.6 | 30.0 | 44.68 | 308.1 | 3.081 |
| 0 | -17.8 | 34.8 | 49.52 | 341.4 | 3.414 |
| 5 | -15.0 | 40.0 | 54.75 | 377.5 | 3.775 |
| 10 | -12.2 | 45.7 | 60.38 | 416.3 | 4.163 |
| 15 | -9.4 | 51.8 | 66.45 | 458.1 | 4.581 |
| 20 | -6.7 | 58.3 | 72.96 | 503.1 | 5.031 |
| 25 | -3.9 | 65.3 | 79.95 | 551.2 | 5.512 |
| 30 | -1.1 | 72.7 | 87.43 | 602.8 | 6.028 |
| 35 | 1.7 | 80.7 | 95.42 | 657.9 | 6.579 |
| 40 | 4.4 | 89.3 | 103.95 | 716.7 | 7.167 |
| 45 | 7.2 | 98.3 | 113.03 | 779.3 | 7.793 |
| 50 | 10.0 | 108.0 | 122.7 | 846.0 | 8.46 |
| 55 | 12.8 | 118.3 | 132.98 | 916.9 | 9.169 |
| 60 | 15.6 | 129.2 | 143.88 | 992.0 | 9.92 |
| 65 | 18.3 | 140.7 | 155.44 | 1071.8 | 10.718 |
| 70 | 21.1 | 153.0 | 167.69 | 1156.2 | 11.562 |
| 75 | 23.9 | 165.9 | 180.64 | 1245.4 | 12.454 |
| 80 | 26.7 | 179.6 | 194.32 | 1339.8 | 13.398 |
| 85 | 29.4 | 194.1 | 208.76 | 1439.4 | 14.394 |
| 90 | 32.2 | 209.3 | 224.0 | 1544.4 | 15.444 |
| 95 | 35.0 | 225.4 | 240.06 | 1655.2 | 16.552 |
| 100 | 37.8 | 242.3 | 256.98 | 1771.8 | 17.718 |
| 105 | 40.6 | 260.1 | 274.78 | 1894.6 | 18.946 |
| 110 | 43.3 | 278.8 | 293.51 | 2023.7 | 20.237 |
| 115 | 46.1 | 298.5 | 313.2 | 2159.4 | 21.594 |
| 120 | 48.9 | 319.2 | 333.89 | 2302.1 | 23.021 |
| 125 | 51.7 | 340.9 | 355.64 | 2452.0 | 24.52 |
| 130 | 54.4 | 363.8 | 378.48 | 2609.5 | 26.095 |
| 135 | 57.2 | 387.8 | 402.48 | 2775.0 | 27.75 |
| 140 | 60.0 | 413.0 | 427.7 | 2948.9 | 29.489 |
| 145 | 62.8 | 439.5 | 454.23 | 3131.8 | 31.318 |
| 150 | 65.6 | 467.5 | 482.17 | 3324.4 | 33.244 |
Properties
| ASHRAE Designation | 507A |
| Safety Classification | A1 (non-flammable, low toxicity) |
| GWP (AR4, 100-yr) | 3985 |
| ODP | 0 |
| Molecular Weight | 98.86 g/mol |
| Boiling Point (1 atm) | -52.1°F / -46.7°C |
| Critical Temperature | 159.1°F / 70.6°C |
| Critical Pressure | 537.4 psia / 37.05 bar |
| Category | HFC Blend |
Common Applications
- Low-temp refrigeration
- Ice machines
- Transport refrigeration