Danfoss Thermal Expansion Valve Instruction Manual

1. Introduction

This manual provides essential information for the proper installation, operation, and maintenance of your Danfoss Thermal Expansion Valve (TXV). These valves are designed for precise control of refrigerant flow in refrigeration and heat exchange systems, ensuring optimal performance and energy efficiency. Please read this manual thoroughly before installation and operation to ensure safe and effective use.

The Danfoss TE2 series thermal expansion valves are specifically designed for fluorinated refrigerants, including R22 and R407C, and are suitable for a wide range of applications.

2. Specifications

The Danfoss TE2 series thermal expansion valves are available in various configurations, primarily differing by their specific model numbers which denote capacity and refrigerant compatibility.

Note: Specific operating ranges (e.g., temperature, pressure) are dependent on the exact model number. Refer to the label on your specific valve for precise details (e.g., "TE2 068Z3208 R22 R407C").

3. Components and Parts

A typical Danfoss TE2 thermal expansion valve consists of the following main components:

• Valve Body: The main brass housing where refrigerant flow is controlled.
• Power Element (Diaphragm Assembly): Contains a charge that responds to temperature changes, actuating the valve.
• Capillary Tube: A thin tube connecting the power element to the sensing bulb.
• Sensing Bulb: Filled with a charge, it senses the superheat of the refrigerant vapor leaving the evaporator.
• Adjusting Stem/Spring: Allows for superheat adjustment.
• Inlet/Outlet Connections: For connecting to the refrigeration system piping.
• External Equalization Line Connection: For connecting the external equalization line to the suction line.

4. Installation and Setup

Proper installation is critical for the correct functioning of the thermal expansion valve. It is recommended that installation be performed by a qualified refrigeration technician.

4.1 Safety Precautions

• Always wear appropriate personal protective equipment (PPE), including safety glasses and gloves.
• Ensure the system is depressurized and isolated before beginning any work.
• Handle refrigerants with care and follow all local regulations.
• Avoid direct contact with refrigerants, as they can cause frostbite.

4.2 Mounting the Valve

1. Location: Install the TXV in the liquid line immediately upstream of the evaporator.
2. Orientation: The valve can typically be installed in any position, but ensure the flow direction arrow on the valve body matches the refrigerant flow.
3. Connections: Use appropriate brazing techniques for copper connections. Ensure connections are clean and free of debris before brazing. Protect the valve body from excessive heat during brazing to prevent damage to internal components.

4.3 Sensing Bulb Installation

The sensing bulb must be installed correctly to accurately measure superheat.

1. Location: Mount the sensing bulb on a horizontal section of the suction line, after the evaporator outlet.
2. Positioning: For suction lines up to 7/8 inch (22 mm) O.D., mount the bulb on top of the pipe. For larger pipes, mount it at the 4 or 8 o'clock position.
3. Securement: Secure the bulb firmly to the suction line using a copper strap or clamps. Ensure good thermal contact by cleaning the pipe surface and, if necessary, applying thermal paste.
4. Insulation: Insulate the sensing bulb and the adjacent section of the suction line to prevent ambient temperature from affecting the superheat measurement.

4.4 External Equalization Line

For valves with external equalization (as indicated by the product video), connect the equalization line from the valve to the suction line, downstream of the sensing bulb. This ensures accurate pressure measurement across the evaporator.

5. Operation

The thermal expansion valve regulates the flow of liquid refrigerant into the evaporator in response to the superheat of the refrigerant vapor leaving the evaporator. This ensures that the evaporator is supplied with enough refrigerant to maintain efficient heat transfer without allowing liquid refrigerant to return to the compressor.

5.1 Superheat Adjustment

The superheat setting of the valve can be adjusted to optimize system performance. This is typically done by turning an adjusting stem on the valve body. Turning the stem clockwise increases the superheat (reduces refrigerant flow), while turning it counter-clockwise decreases the superheat (increases refrigerant flow).

• Increasing Superheat: Turn adjusting stem clockwise.
• Decreasing Superheat: Turn adjusting stem counter-clockwise.

Caution: Superheat adjustment should only be performed by a qualified technician using appropriate tools and gauges. Incorrect adjustment can lead to system inefficiency or damage.

6. Maintenance

Thermal expansion valves are generally robust and require minimal maintenance. However, periodic checks are recommended as part of a comprehensive system maintenance schedule.

• Visual Inspection: Regularly inspect the valve, capillary tube, and sensing bulb for any signs of damage, corrosion, or leaks.
• Thermal Contact: Ensure the sensing bulb maintains good thermal contact with the suction line and that its insulation is intact.
• Superheat Check: Periodically verify the superheat setting to ensure it is within the optimal range for your system. Adjust if necessary.
• Cleanliness: Keep the area around the valve clean and free of debris.

If any issues are detected, consult a qualified refrigeration technician for diagnosis and repair.

7. Troubleshooting

Common issues related to thermal expansion valves and their potential causes:

For complex issues, always consult a certified HVAC/R technician.

8. User Tips

• Professional Installation: Due to the specialized nature of refrigeration components, professional installation is highly recommended to ensure optimal performance and safety.
• Verify Compatibility: Always double-check the valve's model number and refrigerant compatibility (e.g., R22, R407C) against your system requirements before installation.
• Original Parts: Using authentic, new original parts, such as these Danfoss valves, ensures reliability and adherence to performance specifications.

9. Warranty and Support

For warranty information and technical support, please refer to the official Danfoss documentation provided with your product or visit the official Danfoss website. Keep your purchase records for any warranty claims.