Volkswagen Polo Service & Repair Manual: Critical Point
| Vehicle air conditioning systems make use of the
vaporization and condensation process. In this case, one works
with a substance which boils easily, designated as refrigerant. |
| The refrigerant employed is tetrafluoroethane R134a, which
boils at -26.5 °C (-15.7 °F) at a vapor pressure of 1 bar (14.5
psi). |
| The critical point (critical temperature and critical
pressure) is that above which there is no longer a boundary
between liquid and gas. |
| A substance above its critical point is always in the
gaseous state. |
| At temperatures below the critical point, all types of
refrigerant in pressure vessels exhibit both a liquid and a gas
phase, i.e. there is a layer of gas above the liquid. |
| As long as there is still gas present in the container next
to the fluid, pressure is dependent on ambient temperature.
Refer to
→ Chapter „Refrigerant R134a Vapor Pressure Table“. |
 Note
| Different types of refrigerant are never to be mixed. Only
the refrigerant designated for the corresponding A/C system may
be used. |
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Vehicle air conditioning systems make use of the
vaporization and condensation process. In this case, one works
with a substance which boils easily, designated as ref ...
Vehicle air conditioning systems make use of the
vaporization and condensation process. In this case, one works
with a substance which boils easily, designated as ref ...
Other materials:
Opening the tailgate
Fig. 29 In the vehicle key: tailgate release
button
Fig. 30 Opening the tailgate from the
outside
First read and observe the introductory information
and safety warnings
Before opening the tailgate, always remove any items of luggage that are on the
luggage carrier attached to the tailg ...
Contacts in Contact Housing, Repairing
First, open or release if necessary the secondary lock of
the contact housing. Refer to
→ Chapter „Contact Housings, Releasing and Disassembling“.
–
Release contact (primary ...
Infrared Dryer -VAS6879
Definition:
Infrared Dryer -VAS6879-
Product Description:
The infrared dryer is used to dry paste, filler, base paint,
top coats and clear coats on vertical and horizontal surfaces.
...
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Refrigerant R134a Physical Data
Refrigerant R134a Environmental Information