Tightening Flare Nuts; Figure 5-2 Flared-Connection Dimensions; Figure 5-3 Tightening The Flare Nuts; Table 5-1 Flared-Connection Dimensions - Emerson Liebert SRC18 User Manual

4. Carefully inspect the flared pipe end.
• Compare the geometry with Figure 5-1 and the dimensions detailed in Figure 5-2 and Table 5-1.

Figure 5-2 Flared-connection dimensions

Pipe
Vapor (in. O.D.) Liquid (in. O.D.)
1/2
5/8
5.1.2

Tightening Flare Nuts

NOTE
Do not use polyolyester (POE) or any other type of mineral oil as a thread
lubricant. These lubricants are not compatible with PVE oil used in this system
and create oil sludge leading to equipment damage and system malfunction.
1. When connecting the flare nuts, coat the flare (inside and outside) with polyvinyl ether (PVE)
refrigeration oil only.
2. Initially, hand tighten the flare nuts using 3 or 4 turns.
3. Finishing tightening the flare nuts using both a torque wrench and a backup wrench as shown in
Figure 5-3.
Pipe size (in. O.D.)

Figure 5-3 Tightening the flare nuts

Table 5-1 Flared-connection dimensions
Vapor (in.)
1/4 1/8
3/8 1/8
Table 5-2 Tightening torque for flare nuts
Tightening torque (ft-lbs)
∅
1/4
∅
3/8
∅
1/2
∅
5/8
90° 2
A
R=0.4~0.8
"A"
Liquid (in.)
1/16
1/16
Width of flare (A [in.])
13.9 – 18
24.5 – 30.3
39.7 – 47.7
45.5 – 59.2
Union
37
Thickness
Vapor (in.) Liquid (in.)
1/8 1/8
1/16 1/8
1/8
1/8
1/8
1/16
®
Liebert SRC™ User Manual
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