Refrigerant Circuit Pipes And Hoses

For a refrigerant circuit with refrigerant R744, special refrigerant lines and multilayer refrigerant hoses -A- are used. They are designed for the high pressures and temperatures of an R744 A/C system.

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

A -  Refrigerant line or refrigerant hose

B -  Connecting element (there are different versions; refer to CONNECTION POINTS FOR COMPONENTS AND REFRIGERANT LINES )

C -  Inner metallic corrugated tube (installed in the high-pressure hose, for example)

D -  Inner layer that prevents both refrigerant and refrigerant oil leaks and is resistant to both materials (installed in the low-pressure hose, for example)

E -  Intermediate layer

F -  Woven sleeve for pressure absorption

G -  Outer layer

• In its purest state, refrigerant R744 is chemically stable and does not corrode iron, aluminum, and specially developed and therefore suitable plastics, for example. A mixture of refrigerant oil and refrigerant R744 can corrode certain metals, and it can damage or disintegrate certain hose materials and plastics. For this reason use only original parts. Refer to the Parts Information.
• Only use components that are resistant to refrigerant R744 and the respective refrigerant oils. Do not use any components (such as seals and hoses that are made of plastic) which were not clearly assigned. Refer to the Parts Information.
• The pipes and hoses are held together by threaded connections and/or special connections. Refer to CONNECTION POINTS FOR COMPONENTS AND REFRIGERANT LINES  and Refrigerant Circuit (vehicle-specific Service Information).
• Replace the sealing elements (seals, for example) between the components. Refer to CONNECTION POINTS FOR COMPONENTS AND REFRIGERANT LINES . Refer to REFRIGERANT CIRCUIT SEALS , and the Parts Information.
• For threaded connections, observe the tightening specifications. Refer to Refrigerant Circuit (vehicle-specific Service Information).