Volkswagen Polo Service & Repair Manual: Commercial Names and Designations

Volkswagen Polo Service & Repair Manual / Refrrigerant R134a Servicing / A/C System, General Information / Refrigerant R134a Characteristics / Commercial Names and Designations

Refrigerant R134a is currently available under the following trade names:

H-FKW 134a

SUVA 134a

KLEA 134a

Note

Different trade names may be used in other countries.

Of the wide range of refrigerants available, this is the only one which may be used for vehicles. The designations Frigen and Freon are trade names. They also apply to refrigerants which may not be used in automotive vehicles.

Color

Like water, refrigerants are colorless in both vapor and liquid form. Gas is invisible. Only the boundary layer between gas and liquid is visible. (Liquid level in tube of charging cylinder or bubbles in sight glass). Refrigerant R134a fluid may appear colored (milky) in a sight glass. This cloudiness is caused by partially dissolved refrigerant oil and does not indicate a malfunction.

Vapor Pressure

In a partially filled, closed vessel, the quantity of refrigerant evaporating from the surface equals the quantity returning to the liquid state as vapor particles condense. This state of equilibrium occurs under the influence of pressure and is often called vapor pressure. Vapor pressure is dependent on temperature. Refer to → Chapter „Refrigerant R134a Vapor Pressure Table“.

R134a Physical Characteristics

The vapor pressure curves of R134a and other refrigerants are sometimes very similar, therefore it is not possible to make a certain distinction solely by pressure.

With R134a, the A/C compressor is lubricated with special synthetic refrigerant oils, for example. PAG oils (polyalkylene glycol oils).

Affect on Metal

In its pure state, refrigerant R134a is chemically stable and does not corrode iron or aluminum.

Refrigerant impurities such as chlorine compounds however cause corrosion of certain metals and plastics. This can lead to blockage, leaks or deposits on the A/C compressor piston.

Critical Temperature/Pressure

The refrigerant R134a remains chemically stable up to a gas pressure of 39.5 bar (572.9 psi) (corresponding to a temperature of 101 °C (213 °F). Above this temperature, the refrigerant decomposes. Refer to → Chapter „Combustibility“.

Refrigerant R134a Characteristics

...

Water Content

Only very small amounts of water are soluble in liquid refrigerant. On the other hand, refrigerant vapor and water vapor mix in any ratio. Only ...

Other materials:

Electrically Driven A/C Compressor, Flushing
Vehicles with a high voltage system Observe all of the additional warnings for all work performed on vehicles with the high voltage system. Refer to → Electrical Equipment; Rep. Gr.93. ...

Tires, Storing
Storage Room Tire storage must be: Dark, Dry, Cool and Ventilated ...

Tire Pressure Monitoring Sensor without Metal Valve, Removing and Installing, Service Version
Special tools and workshop equipment required Torque Wrench -VAG1410- Perform the Following: Removing – Remove the tire from the disc wheel. Refer to ͛ ...