Volkswagen Golf Service & Repair Manual: Vapour pressure

Volkswagen Golf Service & Repair Manual / Air conditioning system with refrigerant R134a / General notes on air conditioning systems / Characteristics of refrigerant R134a / Vapour pressure

In an enclosed container that is not completely full, refrigerant evaporates as vapour at the surface in a quantity sufficient to form an equilibrium between vapour and liquid. This equilibrium develops under pressure and is often called vapour pressure. The vapour pressure is temperature-dependant → Chapter.

Physical properties of R134a

Because the vapour pressure curves of R134a and other refrigerants are in part very similar, unique identification on the basis of pressure alone is not possible.

The air conditioner compressor used for R134a is lubricated with special synthetic refrigerator oils, such as PAG oils (polyalkylene glycol oils).

Trade names and designations

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

Effects on metal

In its pure state, refrigerant R134a is chemically stable and does not attack iron or aluminium. However, impurities such as chlorine compounds in th ...

Other materials:

Run-flat tyres, PAX, inflating tyre
Observe the following important points when inflating the tyre: – Only inflate after fitting the tyre with valve core installed. Check whether the beads have properly seated at 1 bar. – ...

Removing and installing central locking SAFELOCK function warning lamp -K133
Removing – Remove front door trim panel → General body repairs, interior; Rep. gr.70. – Unclip central locking SAFELOCK function warning lamp ...

Checking steering column for damage
Visual check – Check all steering column parts for damage. Checking function – Check that steering column turns smoothly and easily. – Check whe ...