K90-KPCS-IM-2
18/04/22
- 7 -
Refrigerant
Liquid Line Rise in Feet
10'
15'
20'
25'
30'
PSIG
°F
PSIG
°F
PSIG
°F
PSIG
°F
PSIG
°F
R134a
4.9
2.0
7.4
2.9
9.8
4.1
12.3
5.2
14.7
6.3
R22
4.8
1.6
7.3
2.3
9.7
3.1
12.1
3.8
14.5
4.7
R404A
R507
4.1
1.1
6.1
1.6
8.2
2.1
10.2
2.7
12.2
3.3
R407A
R407A
R407C
R448A
R448A
R449A
R449A
4.3
1.4
6.5
2.1
8.7
2.8
10.8
3.5
12.8
4.1
Refrigerant
Liquid Line Rise in Feet
40'
50'
75'
100'
PSIG
°F
PSIG
°F
PSIG
°F
PSIG
°F
R134a
19.7
8.8
24.6
11.0
36.8
17.0
49.1
23.7
R22
19.4
6.2
24.2
8.0
36.3
12.1
48.4
16.5
R404A
R507
16.3
14.1
20.4
5.6
30.6
8.3
40.8
11.8
R407A
R407A
R407C
R448A
R448A
R449A
R449A
17.82
5.5
21.82
7
32.82
11
43.82
14
Based on 110°F liquid temperature at bottom of riser.
Pressure Loss of Liquid Refrigerant in Liquid Line Risers
If steps of capacity control are supplied on a compressor, provisions must be made for oil return by sizing suction risers to maintain
adequate gas velocities at reduced refrigerant flow.
IMPORTANT PIPING NOTE
REFRIGERANT PIPING (cont’d)
IMPORTANT:
All suction lines outside of the refrigerated space
must be insulated.
During the lower capacity running mode (compressor capacity
control energized) oil will collect in the elbow or at U-bend below
pipe “B”. This will divert the gas and oil to flow up the smaller pipe
“A” at a higher velocity.
Liquid Line
: Horizontal liquid lines should be sized on a basis of
a maximum pressure drop equivalent to a 2°F
(1.1°C)
drop in the
sub-cooling temperature. If the lines must travel up vertically then
adequate sub-cooling must be provided to overcome the vertical
liquid head pressures. A head of two feet of liquid refrigerant is
approximately equivalent to 1 psig
(6.9 kPa)
. Liquid line velocities
should not exceed 300 fpm
(1.52 m/s)
. This will prevent possible
liquid hammering when the solenoid valve closes
IMPORTANT:
When brazing service valves or any components that may be damaged by heat, manufacturer’s installation instructions
must be followed. Wrapping components with a wet cloth will help to prevent damage from heat.
