VW Polo manuals

Volkswagen Polo Service & Repair Manual: Commercial Names and Designations

Refrigerant R134a is currently available under the following trade names:
H-FKW 134a
SUVA 134a
KLEA 134a
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.

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:

General Information
Tongue Weight Specifications The tongue weight specifications on the trailer hitch type label are inspection values and only valid for the hitch. The permitted tongue weight for the vehicle may be less and it must not b ...

This chapter contains information on the following subjects:  → Washing the vehicle  → Washing the vehicle with a high-pressure cleaner  → Cleaning windows and exterior mirrors  → Cleaning and changing windscreen wiper blades  → Waxing and polishing the ve ...

Pressure Gauge, Tests and Measurements
Indicators on pressure gauge 1 -  Temperature scale for refrigerant R134a CF3–CH2F or CH2F–CF3. 2 -  Pressure scale The pressure gauge may have one or more temperature s ...

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