Mazda 3 since 2003
1. Operation and car maintenance
2. Engine
3. Transmission
4. Running gear
5. Steering mechanism
6. Brake system
7. Onboard electric equipment
8. Body
8.1. General information
8.2. Hinged components of a body
8.3. Body glazing
8.4. Seats
8.5. Conditioner and heater
8.5.1. Coolant
8.5.2. Air filter
8.5.3. Block of central air of air
8.5.4. Evaporator
8.5.5. Broad valve
8.5.6. Condenser
8.5.7. Check of a radiator of a heater
8.5.8. Removal and installation of a back air line
8.5.9. Removal and installation of the compressor of central air of air
8.5.10. Dismantling and assembly of the obgonny coupling
8.5.11. Adjustment of the obgonny coupling
8.5.12. Check of the obgonny coupling
8.5.13. Removal and condenser installation
8.5.14. Condenser check
8.5.15. Removal and installation of lines of a coolant (LF)
8.6. Tables



8.5.5. Broad valve

The broad valve provides sharp reduction of pressure of a liquid coolant.
Thus the coolant is sprayed that facilitates evaporation process.
The broad valve also regulates an expense of a coolant submitted to the evaporator.
The expense of a coolant is regulated by size of opening of the spherical valve in the broad valve.
The size of opening is regulated by balance of pressure R-134a on a diaphragm and a resultant pressure force on an evaporator (PI) exit – on the lower part of a diaphragm and force of the spring (Fs) operating on the sharovy valve.
When PI increases, the temperature of the temperature sensor about a diaphragm raises, and Pd warm R-134a – increases by a diaphragm.
When Pd is more than PI + Fs, a diaphragm caves in down, and a shaft attached to the end of a core of the temperature sensor, pushes down the sharovy valve, increasing a coolant expense.

Fig. 8.65. Principle of operation of the broad valve: 1–diaphragm; 2–temperature sensor; 3–shaft; 4–sharovy valve; 5–spring; 6–from the evaporator; 7–to the evaporator; 8–from the condenser; 9–on the condenser; 10-force of a spring; 11-pressure of HFC-134a; 12-pressure on an exit

When the coolant temperature on an exit of the evaporator decreases, PI + Fs becomes more than Pd, the sharovy valve rises, and the expense of a coolant decreases.

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8.5.4. Evaporator
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8.5.6. Condenser