TM 9-4120-398-14
5-11. REFRIGERANT PRESSURE CHECK (cont)
h. Both gages should read the same. Check the reading with the appropriate column in table 52. If the system is even
partially charged, the pressure should be approximately equal to that shown in the table for the appropriate ambient
temperature. If the pressure is considerably less than shown in the table, the system does not contain enough refrigerant to
continue the pressure check; go to leak testing.
TABLE 5-2. PRESSURE-TEMPERATURE RELATIONSHIP OF
SATURATED REFRIGERANT -22
Psig
Deg G
kg/cm2
Deg F
Psig
kg/cm2
Deg C
Deg C
114.2
8.029
2.315
66
18.9
32.93
10
-123
118.3
8.318
68
20.0
2.439
34.68
-11.1
12
2.593
36.89
14
-10.0
70
122.5
8.612
21.1
16
2.739
38.96
-8.9
126.8
72
7.8
22.2
8.915
2.889
41.09
18
131.2
74
23.3
9.225
135.7
76
20
24.4
9.541
3.043
43.28
-6.6
78
140.3
3.180
25.6
9.864
45.23
22
-5.5
47.85
4.3
3.364
24
80
145.0
10.195
3.532
26.7
50.24
3.4
26
10.522
82
149.8
52.70
2.2
3.705
27.8
28
10.877
84
154.7
28.9
86
11.236
159.8
30
1.1
3.883
30.0
55.23
11.594
164.9
31.1
88
4.066
57.83
32
1.1
60.51
4.254
34
2.2
63.27
4.448
32.2
170.1
11.960
90
36
3.3
66.11
175.4
12.332
6.648
33.3
92
38
180.9
12.719
94
34.5
69.02
186.5
13.113
4.853
40
4.4
96
35.6
42
5.5
13.506
71.99
192.1
98
5.062
36.7
75.04
6.6
44
5.276
46
78.18
197.9
7.7
100
13.914
5.497
37.8
14.329
48
81.40
203.8
8.8
102
5.723
38.9
40.0
14.758
209.9
104
15.187
41.4
84.70
216.0
106
5.955
10.0
50
15.630
42.2
88.10
222.3
108
52
6.257
11.1
54
91.5
6.433
12.2
228.7
43.3
16.080
56
110
6.686
13.3
95.1
44.4
16.537
58
235.2
112
6.947
14.5
98.8
241.9
45.6
17.008
114
17.486
60
102.5
248.7
7.206
46.7
15.6
116
62
255.6
7.474
17.971
47.8
16.7
106.3
118
64
17.8
110.2
7.748
i. Turn the mode selector switch to the COOL mode with the temperature control thermostat in the full DECREASE
setting for a few minutes.
With the unit operating, allow gages to stabilize. Take readings of the two gages.
j.
k. Refer to table 51 (Troubleshooting) to isolate malfunction.