Trane BCHE Installation, Operation And Maintenance Manual page 60

Piping and Connections
Figure 51. Typical single-circuit condensing unit: evaporator coil with two distributors
suction line
1. Pitch the liquid line slightly—1 inch/10 feet —so the
refrigerant drains toward the evaporator.
2. Provide one expansion valve per distributor.
3. Slightly pitch the outlet line from the suction header
toward the suction riser— 1 inch/10 feet in the direction
of flow. Use the tube diameter that matches the suction-
header connection. Use a double-elbow configuration
to isolate the TXV bulb from other suction headers.
4. This looks like a trap, but is actually due to the
requirement that the refrigerant gas leaving the coil
flows downward, past the lowest suction-header outlet,
before turning upward.
5. Use the "horizontal" tube diameter as specified in the
condensing unit application manual.
60
Sight
glass
Solenoid
valve
Thermal
expansion
valve (TXV)
Distributor
Evaporator Coil with
Intertwined Circuiting
liquid
line
Filter drier
6. Use the tube diameter recommended for a vertical rise
as specified in the condensing unit application manual.
Assure the top of the riser is higher than the evaporator
coil.
7. Pitch the suction line slightly—1 inch/10 feet —so that
the refrigerant drains toward the evaporator.
8. Insulate the suction line.
9. Only use a "trim" solenoid valve for constant-volume,
humidity-sensitive applications. For all other
applications, install a single solenoid valve (the
"pumpdown" solenoid valve) between the liquid-line
filter drier and the sight glass.
Note: Due to reduced coil volume in condensing units with
micro-channel heat exchanger condenser, do not
use trim solenoid valves for these units.
BCX-SVX002A-EN