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What is the Orifice Tube on the Car Air Conditioning System?

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Understanding the Orifice Tube: A Crucial Component in Your Vehicle's AC System

When it comes to your car's air conditioning system, one vital component plays a significant role in maintaining optimal performance: the orifice tube. In this article, we'll delve into what the orifice tube is and how it works to keep your vehicle cool and comfortable during scorching summer drives.

What is an Orifice Tube?

The orifice tube is a metering device found in some car air conditioning systems. It's a fixed-size, fixed-orifice tube located between the condenser and the evaporator. Unlike other devices that adjust refrigerant flow based on temperature and pressure, the orifice tube restricts refrigerant flow by its fixed size, controlling the amount of refrigerant entering the evaporator coil.


How Does It Work?

The orifice tube functions as a fixed restriction in the refrigerant flow path:

  • Fixed Restriction: With its fixed size, the orifice tube creates a restriction in the refrigerant flow path.

  • Pressure Differential: As high-pressure refrigerant from the condenser enters the orifice tube, its pressure drops significantly due to the restriction.

  • Flow Regulation: The orifice tube controls the flow of refrigerant entering the evaporator, where heat exchange occurs.

  • Maintaining Efficiency: By restricting refrigerant flow, the orifice tube ensures proper cooling efficiency within the evaporator coil.

Common Issues and Symptoms

Though simpler compared to other components, the orifice tube can still experience issues affecting performance:

  • Clogging: Reduced cooling efficiency or inadequate cooling due to debris or contaminants blocking the orifice.

  • Failure: If the orifice tube corrodes or sustains damage, it can lead to complete blockage or improper refrigerant flow.

In summary, the orifice tube is a critical component in your car's AC system. If you suspect an issue with this component, it's essential to have your vehicle inspected and serviced by a qualified technician to diagnose and address the problem promptly. You can book a diagnosis and potential replacement online at 

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