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:

ParkPilot menu
First read and observe the introductory information and safety warnings ParkPilot settings in the infotainment system menu Switch on the ignition. If necessary, switch on the infotainment system. Press the button. Touch the function button. Touch the Parking and manoeuvering fu ...

Removing and installing rear underbody cover – petrol/diesel
Note The removal and installation procedures may have to be modified slightly depending on engine fitted. – Loosen lock washer -3-. – Unclip spreader rivet -2- and remove bolt -4-. – Remove rea ...

Special driving situations
Fig. 170 A: vehicle in a bend B: motorbike in front is outside the range of the radar sensor Fig. 171 C: vehicle is changing lanes. D: turning vehicle, stationary vehicle First read and observe the introductory information and safety warnings The Adaptive Cruise Control (ACC) has physica ...