Use and Care Manual

Page 11 mrcool.com
Unit Installation - OPTION 1: Conventional Weld / Flare Line Set
Conventional Line Set Installation
Specification of Connection Pipe
Piping Preparation
1.
WELD Type Complete Unit Replacement
All cut ends are to be round, burr free, and cleaned. Failure to follow this
practice increases the chances for refrigerant leakage. Line set size matches
service valve connection. DO NOT crimp service valve connector when pipe is
smaller than connector. See diagram below.
2. Screw Connection
Copper Piping
Oil Applied (to reduce
friction with the flare nut)
Oil Applied (improves
air-tight seal)
Fig. 2.5
Fig. 2.4
Fig. 2.3
Torque Wrench
Spanner
Piping Union
Flare Nut
Model
External diameter (inch)
Vapor pipe Liquid pipe
3/4 3/8
Pipe diameter (inch)
Tightening torque (N·m)
1/4
15-30
3/8
35-40
1/2
45-50
5/8
60-65
3/4
70-75
7/8
80-85
MDUI18048 / MDUI18060
Purge with
Nitrogen
Must open stop valves
after pulling vacuum
and before powering
on unit
Weld joint
Weld joint
Air Handler
MRCOOL Universal® Series
DC Inverter
Open stop valves with allen
wrench only after nishing
lineset connections and before
powering on the unit
Must install lter
drier bi ow with this
installation type
Must Purge with Nitrogen
before brazing joints
Must Purge with
Nitrogen before
brazing joints