R-717 (ammonia) · NH3
R-717 (anhydrous ammonia, CAS 7664-41-7) is a single-component refrigerant; this page gives its saturation pressure and saturated liquid and vapour densities from -40 to 60 °C.
Saturation pressure and saturated liquid and vapour densities are computed from CoolProp==6.6.0 - reference Helmholtz equation of state for Ammonia and tabulated over -40–60 °C.
- Also known as
- Anhydrous ammonia, Ammonia, R717, Azane
- CAS number
- 7664-41-7
- Tabulated range
- -40–60 °C · saturation line
- Refrigerant
- R-717
- Chemical name
- anhydrous ammonia
- GWP (100-yr)
- 1
- ASHRAE 34 class
- B2L
GWP 1 — WMO 2022 100-year GWP (basis attributed by the U.S. EPA Technology Transitions GWP Reference Table). U.S. EPA - Technology Transitions GWP Reference Table. U.S. Environmental Protection Agency, Technology Transitions GWP Reference Table: R-717 (ammonia) 100-year GWP = 1 (table reference WMO 2022). https://www.epa.gov/climate-hfcs-reduction/technology-transitions-gwp-reference-table
ASHRAE 34 B2L — ANSI/ASHRAE Standard 34 safety group classification. ANSI/ASHRAE Standard 34 - Designation and Safety Classification of Refrigerants. ANSI/ASHRAE Standard 34-2022, Designation and Safety Classification of Refrigerants: R-717 (ammonia) assigned safety group B2L.
- Saturation pressure
- 10.027bar
- Pressure
- 1002.7kPa
- Gauge
- 130.7psig
- Liquid density
- 603.0kg/m³
- Vapour density
- 7.80kg/m³
Read the saturation line either way
Set a temperature to read its saturation pressure and densities, or set a pressure to read the saturation temperature. Every number is interpolated from the committed table below and clamped to the validated -40–60 °C range — nothing is computed from a property model in your browser.
Values are interpolated along the tabulated saturation line below — both the temperature and the pressure stay within the validated -40–60 °C range and are never extrapolated.
- Saturation temp
- 25.0 °C
- Saturation pressure
- 10.027 bar
- Pressure
- 1002.7 kPa
- Gauge pressure
- 130.7 psig
- Liquid density
- 603.0 kg/m³
- Vapour density
- 7.80 kg/m³
Every tabulated point
Saturation pressure (absolute, shown in kPa and bar, with the gauge value in psig at standard atmosphere) and the saturated liquid and vapour densities at each temperature. A negative psig is a partial vacuum below one atmosphere.
| T °C | p kPa | p bar | p psig | ρ liq kg/m³ | ρ vap kg/m³ |
|---|---|---|---|---|---|
| -40 | 71.6 | 0.716 | −4.3 | 689.8 | 0.64 |
| -35 | 93.0 | 0.930 | −1.2 | 683.7 | 0.82 |
| -30 | 119.4 | 1.194 | 2.6 | 677.5 | 1.04 |
| -25 | 151.4 | 1.514 | 7.3 | 671.3 | 1.30 |
| -20 | 190.0 | 1.900 | 12.9 | 665.0 | 1.60 |
| -15 | 236.1 | 2.361 | 19.5 | 658.5 | 1.97 |
| -10 | 290.6 | 2.906 | 27.5 | 652.0 | 2.39 |
| -5 | 354.7 | 3.547 | 36.7 | 645.4 | 2.88 |
| 0 | 429.3 | 4.293 | 47.6 | 638.6 | 3.46 |
| 5 | 515.6 | 5.156 | 60.1 | 631.8 | 4.11 |
| 10 | 614.8 | 6.148 | 74.5 | 624.8 | 4.87 |
| 15 | 728.2 | 7.282 | 90.9 | 617.7 | 5.72 |
| 20 | 857.0 | 8.570 | 109.6 | 610.4 | 6.70 |
| 25 | 1002.7 | 10.027 | 130.7 | 603.0 | 7.80 |
| 30 | 1166.5 | 11.665 | 154.5 | 595.4 | 9.05 |
| 35 | 1350.0 | 13.500 | 181.1 | 587.6 | 10.45 |
| 40 | 1554.5 | 15.545 | 210.8 | 579.6 | 12.02 |
| 45 | 1781.7 | 17.817 | 243.7 | 571.4 | 13.79 |
| 50 | 2033.0 | 20.330 | 280.2 | 563.0 | 15.78 |
| 55 | 2310.0 | 23.100 | 320.3 | 554.3 | 18.00 |
| 60 | 2614.5 | 26.145 | 364.5 | 545.3 | 20.48 |
R-717 saturation pressure at a glance
At -20 °C, R-717 saturation pressure is about 1.90 bar (190 kPa; 12.9 psig). At 0 °C, R-717 saturation pressure is about 4.29 bar (429 kPa; 47.6 psig). At 25 °C, R-717 saturation pressure is about 10.03 bar (1003 kPa; 130.7 psig). At 40 °C, R-717 saturation pressure is about 15.55 bar (1555 kPa; 210.8 psig).
Where the numbers come from
Every value on this page is computed by a deterministic equation of state — none is entered by hand. The generating method and the references it is checked against:
- ▸NIST Chemistry WebBook, SRD 69 - Thermophysical Properties of Fluid Systems (REFPROP-derived saturation tables), ammonia (CAS 7664-41-7)
- ▸CoolProp 6.6.0 - reference Helmholtz equation of state for ammonia (Tillner-Roth, Harms-Watzenberg & Baehr, 1993)
- ▸U.S. EPA - Technology Transitions GWP Reference Table (100-year GWP, WMO 2022 reference)
- ▸ANSI/ASHRAE Standard 34-2022 - Designation and Safety Classification of Refrigerants
Model: CoolProp==6.6.0 - reference Helmholtz equation of state for Ammonia · Generated 2026-06-07
The committed data file for this page is published as JSON on GitHub under CC BY 4.0.
Checked against cited values
The equation of state is cross-checked against independently cited saturation points. The page is published only because every check passes.
| Property / point | Saturation pressure · 25 °C |
| Cited reference value | 1002.7 kPa |
| Model computed | 1002.69 kPa |
| Error vs reference | 0.001% (tolerance 1%) |
NIST Chemistry WebBook, SRD 69 - Thermophysical Properties of Fluid Systems. NIST Chemistry WebBook, SRD 69, Thermophysical Properties of Fluid Systems, ammonia (R-717) (CAS 7664-41-7), saturation curve at 25 degC: saturation pressure = 1002.7 kPa. https://webbook.nist.gov/cgi/fluid.cgi?ID=C7664417&Action=Page
| Property / point | Saturated liquid density · 25 °C |
| Cited reference value | 602.96 kg/m3 |
| Model computed | 602.96 kg/m3 |
| Error vs reference | 0% (tolerance 1%) |
NIST Chemistry WebBook, SRD 69 - Thermophysical Properties of Fluid Systems. NIST Chemistry WebBook, SRD 69, Thermophysical Properties of Fluid Systems, ammonia (R-717) (CAS 7664-41-7), saturation curve at 25 degC: saturated liquid density = 602.96 kg/m3. https://webbook.nist.gov/cgi/fluid.cgi?ID=C7664417&Action=Page
Before you use these numbers
- ▸CoolProp reference Helmholtz equation of state (Tillner-Roth, Harms-Watzenberg & Baehr, 1993) for ammonia. This page is anhydrous ammonia (R-717), the single-component refrigerant; for ammonia dissolved in water (aqueous ammonia / ammonium hydroxide solutions), see the aqueous ammonia hub. Saturation properties only, tabulated from -40 to +60 degC; superheated and single-phase data are out of scope for this page. The critical point is 132.41 degC / 11363.4 kPa, well above the table top, so every tabulated state is sub-critical. Values are for preliminary design; verify against vendor data for critical service.
- ▸Saturation properties only — these are two-phase (saturation-line) values; superheated and sub-cooled single-phase data are out of scope for this page. The critical point is 132.41 °C / 11363.4 kPa, above the tabulated range.
- ▸Values are tabulated only inside the -40–60 °C range shown; the equation of state is not extrapolated beyond it here.
- ▸Use for preliminary design; verify for critical service.
- Aqueous ammonia (NH3) solution properties — Density and specific gravity of ammonia dissolved in water vs concentration and temperature - the aqueous solution, not this anhydrous refrigerant.
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