1. The Pressure / Temperature Chart

2. R-134a

3. Pressure / Temperature Chart
The PT Chart is a TOOL, it will help you determine the Saturation Temperature of the refrigerant in your system.
Once you know the saturation temperature, you are then able to determine the state of the refrigerant in your system!

4. Pressure / Temperature Chart
Example:
What is the Saturation Temperature of the refrigerant on the High Side of a system if the Discharge Pressure is Bar, ( PSIG)?

5. 47.8º C (118° F) is the Saturation Temperature
Degrees F
Degrees C
PSIG
BARS
-40
-40.0
14.50
1.00 56
13.3
52.30
3.61
-38
-38.9
13.70
0.95 58
14.4
55.00
3.80
-36
-37.8
12.80
0.88 60
15.6
57.50
3.97
-34
-36.7
11.80
0.81 62
16.7
60.10
4.15
-32
-35.6
10.80
0.75 64
17.8
62.70
4.33
-30
-34.4
9.70
0.67 66
18.9
65.50
4.52
-28
-33.3
8.60
0.59 68
20.0
68.30
4.71
-26
-32.2
7.70
0.53 70
21.1
71.20
4.91
-24
-31.1
6.20
0.43 72
22.2
74.20
5.12
-22
-30.0
4.90
0.34 74
23.3
77.20
5.33
-20
-28.9
3.60
0.25 76
24.4
80.30
5.54
-18
-27.8
2.30
0.16 78
25.6
83.50
5.76
-16
-26.7
0.80
0.06 80
26.7
86.80
5.99
-14
-25.6
0.30
0.02 82
27.8
90.20
6.22
-12
-24.4
1.10
0.08 84
28.9
93.60
6.46
-10
-23.3
1.90
0.13 86
30.0
97.10
6.70 -8
-22.2
2.80
0.19 88
31.1
100.70
6.95 -6
-21.1 90
32.2
104.40
7.20 -4
-20.0
4.50
0.31 92
33.3
108.20
7.47 -2
-18.9
5.50
0.38 94
34.4
112.10
7.73
-17.8
45.50
3.14
146
63.3
249.20
17.19 52
11.1
47.70
3.29
148
64.4
256.00
17.66 54
12.2
50.10
3.46
150
65.6
263.00
18.15
Underlined Values Indicate Vaccum (IN of HG, MM of Mercury)
6.50
0.45 96
35.6
116.10
8.01 2
-16.7
7.50
0.52 98
36.7
120.10
8.29 4
-15.6
8.50
0.59
100
37.8
124.30
8.58 6
-14.4
9.60
0.66
102
38.9
128.50
8.87 8
-13.3
10.80
0.75
104
40.0
132.90
9.17 10
-12.2
12.00
0.83
106
41.1
137.30
9.47 12
-11.1
13.10
0.90
108
42.2
142.80
9.85 14
-10.0
14.40
0.99
110
43.3
146.50
10.11 16
-8.9
15.70
1.08
112
44.4
151.30
10.44 18
-7.8
17.00
1.17
114
45.6
156.10
10.77 20
-6.7
18.40
1.27
116
46.7
161.10
11.12 22
-5.6
19.90
1.37
118
47.8
166.10
11.46 24
-4.4
21.40
1.48
120
48.9
171.30
11.82 26
-3.3
22.90
1.58
122
50.0
176.60
12.19 28
-2.2
24.50
1.69
124
51.1
182.00
12.56 30
-1.1
26.10
1.80
126
52.2
187.50
12.94 32
0.0
27.80
1.92
128
53.3
193.10
13.32 34
1.1
29.50
2.04
130
54.4
198.90
13.72 36
2.2
31.30
2.16
132
55.6
204.70
14.12 38
3.3
33.20
2.29
134
56.7
210.70
14.54 40
4.4
35.10
2.42
136
57.8
216.80
14.96 42
5.6
37.00
2.55
138
58.9
223.00
15.39 44
6.7
39.10
2.70
140
60.0
229.40
15.83 46
7.8
41.10
2.84
142
61.1
235.80
16.27 48
8.9
43.30
2.99
144
62.2
242.40
16.73 50
10.0
47.8º C (118° F) is the Saturation Temperature