GMV DC Inverter VRF 
28 
3.4 Pipeline Installation and Insulation 
3.4.1 Pipeline Installation of Refrigeration System   
(1)  Before welding the pipeline sealing cap, please make sure there's no refrigerant in pipeline. 
If welding it directly, it may cause unnecessary property damage or personal injury. 
(2)  Conform to the following principles during pipe connection: Connection pipeline should be 
as short as possible. The height difference between indoor and outdoor units should be as 
short as possible. Keep number of bends as little as possible. The radius of curvature should 
be as large as possible. 
(3)  Weld the connection pipes between indoor and outdoor unit. Please strictly conform to the 
requirements for welding process. Rosin joints and pin holes are not allowable. 
(4)  When laying the pipes, be careful not to deform them. The radius of bending parts should be 
more than 200mm. The pipes can't be repeatedly bent or stretched, otherwise the material 
will get harden. Do not bend or stretch the pipe over three times at the same position. 
(5)  Please use a torque wrench to connect union nut on the indoor unit. See the Fig
. 3.4.1 as 
below. 
 
Fig. 3.4.1 
1)  Align the expansion end of copper pipe with the center of threaded joint. Tighten the flare 
nuts with your hands. 
2)  Tighten the flare nuts with torque wrench until you hear "click" sound. 
3)  Use sponge to wrap the connecting pipe and joints without thermal insulation and tie it up 
with plastic tape. 
4)  A mounting support for the connection pipe is required. 
5)  The curvature degree of connection pipe should not be small, otherwise the pipe might 
crack. Installation personnel should use tube bender when bending the pipe. 
6)  Don't forcibly stretch the pipe joint, otherwise indoor capillary or other pipes might be 
damaged and lead to refrigerant leakage. 
3.4.2 Installation of the manifold 
The main function of manifold is used to shunt the refrigerant. Pay attention to the following 
points when installing it: 
(1)  When installing the manifold, it should be as close as possible to the indoor unit to reduce 
the influence of the indoor unit manifold on the refrigerant distribution.