Emerson Xtreme Density Manuel D’Utilisation

The main supply and return lines to and from the XDP/XDC must be sloped downward toward the 

XDP/XDC at a rate of 1-2" per 20 feet (25-51mm per 6m) of pipe run. Horizontal connector lines 

should also be sloped downward from the cooling modules toward the main supply and return lines.

To ensure the XDP/XDC pumps operate within the optimum range, some installations require one or 

more bypass flow controller(s). These devices are added to the field piping, and simulate the flow of 

additional cooling modules.
Each bypass flow controller should be installed with one shutoff valve to allow the controller to be dis-

abled when cooling modules are added to a Liebert XD system.
If bypass flow controllers are required, they should be connected between the main supply and the 

main return lines of the field piping. The connection points to the main supply and return lines should 

be in a convenient and accessible location between the Liebert XDP/Liebert XDC and the first Liebert 

XD module in the circuit. See Figures 26 and 25 for piping details of the bypass flow controller. 
Refer to Table 6 to determine the number of bypass flow controllers needed, based on the total nomi-

nal cooling capacity of the cooling modules in each Liebert XD system.

32 to 63

3

N/A

64 to 95

2

2

96 to 127

1

1

128 to 160

0

0