Piping

2.5Piping Details—Shut-Off/Isolation Valves

To allow for maintenance of the Liebert XDP, isolation valves must be installed on the chilled water circuit (see Figure 20).

Figure 20 General piping details

Return

Supply Return

Supply

Liebert

XDP A

Liebert

XDP B

Floor

 

Isolation

Isolation

valves

valves

Building Chilled Water Supply

Building Chilled Water Return

2.5.1Piping Installation Method

All piping should be installed with high temperature brazed joints. Prevailing good refrigeration prac- tices should be employed for piping supports, leak testing, dehydration and charging. Emerson Net- work Power highly recommends venting the pressure relief of the Liebert XDP (located at the top of the receiver) outside of the conditioned space where it is open to the atmosphere.

2.5.2Piping Mains

All refrigeration piping mains, both supply and return, should be installed with a downward pitch toward the Liebert XDP of 1-2" for every 20 feet (25.4-51mm per 6m) of pipe run.

Install a 20-40 mesh strainer on the chilled water supply to the Liebert XDP. The strainer is needed to prevent particles in the chilled water from entering the heat exchanger of the Liebert XDP.

2.5.3Evacuation and Leak Check

1.Open all service valves, including those located outside of the Liebert XDP.

2.Place 150 psig (1034kPa; 10.34 bars) of dry nitrogen with a tracer of R-134a in the system.

NOTICE

Risk of overpressurization. Can cause equipment damage.

Do not exceed 150 psig (1034 kPa; 10.34 bars) in the R-134a circuit.

3.Check the system for leaks with a suitable leak finder

4.After completion of the leak testing, release the test pressure (per local code) and connect to vacuum pump(s) at the Schrader valves.

5.After four hours of pulling a deep vacuum, check the vacuum level and if it has not changed, break the vacuum with dry nitrogen.

6.Pull a second vacuum to 250 microns or less. Recheck the vacuum level after 2 hours.

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Liebert XDP Piping Details-Shut-Off/Isolation Valves, Piping Installation Method, Piping Mains, Evacuation and Leak Check