Installation and Maintenance Manual

30 VRF-SVN33A-EN
Leak Testing Pipe Connections
Use the following procedure for leak testing pipe connections.
1. Connect the refrigerant manifold gauge hoses to the liquid side and gas side service ports on
the unit, and connect the center hose to a nitrogen gas tank fitted with a pressure regulator (see
Figure 20).
Figure 20. Leak testing pipe connections with a manifold gauge
2. Fill the lines with nitrogen to no more than 594.6 psi (4.1 MPa).
3. Monitor the pressure periodically for a minimum of 24 hours. If the pressure drops, use soapy
water to check for leaks. Bubbles will occur if joints are not tight.
4. Release pressure in pipelines gradually.
5. Repair leaks.
6. Repeat the previous steps until the pressure remains constant.
7. Maintain 145 psi (1.0 MPa) of pressure for 15 minutes and check for further leakage. If the
pressure drops, check for leaks and repair them. Repeat this step as necessary until 145 psi
(1.0 MPa) of pressure is maintained for 15 minutes.
8. Remove hoses from service ports.
NOTICE
Refrigerant Pipe Damage!
When performing a leak test, use a pressure regulator to prevent an excess amount of nitrogen
(over 594.6 psi [4.1 MPa]) from entering the pipes. If the pipe is filled with more than the
specified amount of nitrogen in a short period of time, pipe damage may occur.
High-pressure side
Nitrogen gas
Low-pressure side
Service ports
Low-pressure (gas
side) service valve
High-pressure (liquid
side) service valve