27
Table 5 – Equivalent Lengths of Fittings
Line
Size
OD
(in)
Equivalent Lengths of Refrigerant Pipe (feet)
Elbow
90°
Standard
Elbow
90°
Long
Radius
Elbow
90°
Street
Elbow
45°
Standard
Elbow
45°
Street
⅞
2.0
1.4
3.2
0.9
1.6
1⅛
2.6
1.7
4.1
1.3
2.1
1⅜
3.3
2.3
5.6
1.7
3.0
1⅝
4.0
2.6
6.3
2.1
3.4
2⅛
5.0
3.3
8.2
2.6
4.5
2⅝
6.0
4.1
10.0
3.2
5.2
3⅛
7.5
5.0
12.0
4.0
6.4
3⅝
9.0
5.9
15.0
4.7
7.3
4⅛
10.0
6.7
17.0
5.2
8.5
Liquid Line Sizing
The liquid line diameter should be as small as
possible while maintaining acceptable pressure drop.
This is necessary to minimize refrigerant charge. The
total length between the chiller unit and the air-
cooled condenser must not exceed 200 actual feet
or 300 equivalent feet.
Liquid line risers in the system will require an
additional 0.5 psig pressure drop per foot of vertical
rise. When it is necessary to have a liquid line riser,
make the vertical run immediately after the
condenser before any additional restrictions. The
liquid line risers must not exceed 15 feet in height
from the condenser liquid line connection (see
Figure 35). The liquid line does not require pitching.
Install a pressure tap valve at the condenser to
facilitate measuring pressure for service.
Liquid lines do not typically require insulation.
However, if exposing the lines to solar heat gain or
temperatures exceeding 110 °F, there is a negative
effect on sub-cooling. In these situations, insulate
the liquid lines.
