Line Sizing; Liquid Line Sizing Steps - Trane R Series Installation, Operation And Maintenance Manual

Installation - Mechanical — Remote Evaporator Option

Line Sizing

To determine the appropriate outside diameter for field
installed liquid and suction lines, it is first necessary to
establish the equivalent length of pipe for each line. It is
also necessary to know the capacity (tons) of each circuit.
Circuit capacities for each RTAC unit are listed in
p. 12 through Table 10, p.
Table 30. Equivalent lengths of non-ferrous valves and
fittings (feet)
Line Size Globe Short Angle
Inches OD Valve Valve
1-1/8 87 29
1-3/8 102 33
1-5/8 115 34
2-1/8 141 39
2-5/8 159 44
3-1/8 185 53
3-5/8 216 66
4-1/8 248 76

Liquid Line Sizing Steps

The steps to compute liquid line size are as follows:
1. Compute the actual length of field installed piping.
2. Multiply the length from step # 1 by 1.5 to estimate the
equivalent length.
Table 31. Required length of field installed suction line accumulator (ft)
70 Ton Circuit
Actual Feet
of field
1 3/8" 1 5/8"
installed
Length of 3 5/8" Suction
liquid line
Accumulator
10 43
20 45
30 46
40 48
50 49
60 51
70 52
80 53
90 55
100 56
110 58
120 59
130 61
140 62
150 64
160 65
170 66
180 68
190 69
200 71
(a) Circuit 2 of 155 ton premium unit requires ad additional 10 feet of suction accumulator length.
RTAC-SVX01J-EN
Table 1,
21.
Long
Short Radius Radius
ELL ELL
2.7 1.9
3.2 2.2
3.8 2.6
5.2 3.4
6.5 4.2
8 5.1
10 6.3
12 7.3
(a)
85 Ton Circuit
O.D. of Field Installed Liquid Line
2 1/8" 1 3/8" 1 5/8"
Length of 3 5/8" Suction
Accumulator
44 45 52
46 49 53
48 52 54
50 55 56
52 59 57
54 62 59
56 65 60
58 69 62
60 72 63
62 75 64
64 79 66
66 82 67
68 85 69
70 89 70
72 92 72
74 95 73
76 99 75
78 102 76
79 105 77
81 109 79
3. See Table 29, p. 58
corresponding to equivalent length computed in step
2 for height and leaving water temperature of interest.
Note: If condenser is at same elevation or above evap,
use 0 ft. column.
4. With the outside diameter found in step # 3, use
Table 30, p. 59
each fitting in the field installed piping.
5. Add equivalent lengths of all field installed elbows and
valves.
6. Add the length found in step # 5 to the actual length
from step # 1.This is your new equivalent line length.
7. Using Table 29, p. 58
that corresponds to the new equivalent line length
from step # 6. If it is the same as step #3, this is the final
equivalent length. Otherwise, proceed to the next step.
8. Using Table 30, p. 59
found in step # 7, find the equivalent line length of each
valve and fitting, and sum them.
9. Add the length found in step # 8 to the actual length
from step # 1.This is the new equivalent line length.
10. With the equivalent line length found in step # 9, use
Table 29, p. 58
the liquid lines. If the same as in step #7, this is your
final equivalent line length. Otherwise, repeat step #7.
Note: Location and quantity of suction accumulator is
dependent upon the unit configuration.
100 Ton Circuit
2 1/8" 1 5/8" 2 1/8"
Length of 4 1/8" Suction
Accumulator
52 53 43
54 57 45
56 60 46
58 63 48
60 67 49
62 70 51
64 73 53
66 77 54
68 80 56
70 83 57
72 87 59
74 90 60
76 93 62
78 97 63
80 100 65
82 103 67
84 107 68
86 110 70
88 113 71
90 117 73
to determine outside diameter
to determine the equivalent lengths of
again, find the outside diameter
and the new outside diameter
to select the proper outside diameter for
120 Ton Circuit
2 5/8" 1 5/8" 2 1/8"
Length of 4 1/8" Suction
Accumulator
44 46 52
47 50 53
49 53 55
52 57 56
55 61 58
57 65 59
60 69 61
62 73 62
65 77 64
68 81 66
70 85 67
73 89 69
75 93 70
78 97 72
81 101 73
83 105 75
86 108 76
88 112 78
91 116 80
94 120 81
2 5/8"
53 54
55 58
58 62
60 66
63 70
66 74
68 78
71 81
73 85
76 89
79 93
81 97
84 101
86 105
89 109
92 113
94 117
97 121
99 125
102 129
59