GP Series Portable Chillers Chapter 3: Installation 17 of 64
leaving water temperature range is also required. See Figure 2 on page 17 for lengths of
refrigerant valves and fittings.
Liquid Line Sizing. The liquid line should be sized as small as possible while maintaining
acceptable pressure drop to minimize the refrigerant charge. Liquid line risers must not
exceed 15 feet from the base of the air-cooled condenser. Horizontal runs do not require a
pitch. Insulation is not required unless the line is installed in a high ambient area, i.e., boiler
room. Install a liquid line-charging valve to facilitate refrigerant charging. See Figure 3 on
page 17 for sizing information. See Figure 5 on page 19 for charge determination.
Discharge Line Sizing. For horizontal runs, the discharge line should be pitched downward,
in the direction of flow, at a rate of 1/2” for every 10 feet. This will allow oil to flow towards
the condenser. Discharge line sizing is based on the velocity required for sufficient oil return
back to the compressor. See Figure 4 on page 18 for discharge line sizing.
Figure 2: Equivalent Length in Feet for Valves and Fittings
Line Size
OD (inches) Angle
Valve Short
Radius EL Long
Radius EL
3/8 24 4 2.8
1/2 24 4.7 3.2
5/8 25 5.7 3.9
3/4 25 6.5 4.5
7/8 28 7.8 5.3
1-1/8 29 2.7 1.9
1-3/8 33 3.2 2.2
1-5/8 34 3.8 2.6
2-1/8 39 5.2 3.4
2-5/8 44 6.5 4.2
Figure 3: Liquid Line Sizing
5 TON CIRCUIT 7.5 TON CIRCUIT
Liquid Line Size (OD") Liquid Line Size (OD")
Total Equiv.
Length (Ft)
Horizontal
or
Downflow Upflow
1-5 Ft Upflow
6-10 Ft Upflow
11-15 Ft
Total Equiv.
Length (Ft)
Horizontal
or
Downflow Upflow
1-5 Ft Upflow
6-10 Ft Upflow
11-15 Ft
25 1/2 1/2 1/2 1/2 25 5/8 5/8 5/8 5/8
50 1/2 1/2 1/2 1/2 50 5/8 5/8 5/8 5/8
75 1/2 1/2 1/2 1/2 75 5/8 5/8 5/8 5/8
100 1/2 1/2 1/2 5/8 100 5/8 5/8 5/8 5/8
125 1/2 1/2 1/2 5/8 125 5/8 5/8 5/8 5/8
150 1/2 1/2 5/8 5/8 150 5/8 5/8 5/8 5/8
175 1/2 5/8 5/8 5/8 175 5/8 5/8 5/8 3/4
200 1/2 5/8 5/8 5/8 200 5/8 5/8 5/8 3/4
225 1/2 5/8 5/8 5/8 225 5/8 5/8 5/8 3/4
250 5/8 5/8 5/8 5/8 250 5/8 5/8 3/4 3/4
275 5/8 5/8 5/8 5/8 275 5/8 5/8 3/4 3/4
300 5/8 5/8 5/8 5/8 300 5/8 5/8 3/4 3/4