1. Introduction
This user manual provides essential information for the safe and efficient installation, operation, and maintenance of the Danfoss TGE series thermostatic expansion valve. The Danfoss TGE valve is a high-performance component designed for precise control of refrigerant flow in refrigeration and air conditioning systems, specifically optimized for R410A refrigerant. Adhering to these instructions will ensure optimal performance and longevity of the product.
2. Product Overview
The Danfoss TGE expansion valve is a compact and robust component engineered for superior performance. It features a stainless steel power element, a hermetic design, and a bi-directional flow capability, making it suitable for heat pump applications. The valve ensures accurate superheat control and stable operation across various load conditions.
Figure 2.1: This image displays the Danfoss TGE series expansion valve, featuring a brass body with copper connections, a coiled capillary tube, and a sensing bulb. The valve is designed for precise refrigerant flow control in refrigeration and air conditioning systems.
Key Features:
- Optimized for R410A refrigerant.
- Hermetic design for enhanced reliability.
- Bi-directional flow for heat pump applications.
- Precise superheat control.
- Robust construction for long service life.
- Inlet Connection Type: Outside Diameter Flared.
3. Setup and Installation
Installation should only be performed by qualified personnel familiar with refrigeration systems and safety procedures. Ensure the system is depressurized and isolated before beginning installation.
Installation Steps:
- System Preparation: Ensure the refrigeration system is clean and free of contaminants. Flush the system if necessary.
- Valve Placement: Install the expansion valve in the liquid line, as close as possible to the evaporator inlet. Ensure the flow direction matches the arrow on the valve body.
- Brazing: Use appropriate brazing techniques to connect the valve to the liquid line. Protect the valve body and power element from excessive heat during brazing using a wet cloth or heat sink paste.
- Sensing Bulb Installation: Securely attach the sensing bulb to the suction line, typically after the evaporator. Ensure good thermal contact by cleaning the pipe surface and using a clamp. Insulate the bulb to prevent ambient temperature influences.
- Leak Testing: After installation, perform a thorough leak test on all connections using an appropriate leak detection method.
- Evacuation: Evacuate the system to a deep vacuum to remove all non-condensable gases and moisture.
- Refrigerant Charge: Charge the system with the correct amount and type of R410A refrigerant according to the system manufacturer's specifications.
4. Operating Principles
The Danfoss TGE thermostatic expansion valve regulates the flow of liquid refrigerant into the evaporator based on the superheat of the refrigerant vapor leaving the evaporator. The sensing bulb, filled with a charge, responds to the temperature of the suction line. As the superheat increases, the pressure in the bulb increases, opening the valve further to allow more refrigerant into the evaporator. Conversely, as superheat decreases, the valve closes to reduce refrigerant flow. This dynamic control ensures the evaporator is fully utilized without allowing liquid refrigerant to return to the compressor.
5. Maintenance
The Danfoss TGE expansion valve is designed for minimal maintenance. However, regular system checks are recommended to ensure optimal performance of the entire refrigeration circuit.
Recommended Maintenance Practices:
- Regular System Checks: Periodically check the superheat settings and system pressures to ensure the valve is operating within its design parameters.
- Cleanliness: Ensure the refrigeration system remains clean and free of contaminants, as dirt or debris can impair valve operation.
- Insulation: Verify that the sensing bulb insulation is intact and providing proper thermal isolation from ambient temperatures.
- Leak Detection: Routinely check for refrigerant leaks around the valve connections.
Do not attempt to disassemble the valve. If the valve is suspected to be faulty, it should be replaced by a qualified technician.
6. Troubleshooting
This section outlines common issues related to expansion valve operation and potential solutions. Always consult a qualified refrigeration technician for diagnosis and repair.
| Problem | Possible Cause | Solution |
|---|---|---|
| High Superheat / Starved Evaporator | Low refrigerant charge, restricted liquid line, clogged filter drier, faulty sensing bulb, valve stuck closed. | Check refrigerant charge, inspect liquid line and filter drier, verify sensing bulb contact, replace valve if stuck. |
| Low Superheat / Flooded Evaporator | Overcharge of refrigerant, sensing bulb improperly installed/insulated, valve stuck open, external equalizer line blocked. | Adjust refrigerant charge, re-install/insulate sensing bulb, clear equalizer line, replace valve if stuck. |
| Fluctuating Superheat | Improper sensing bulb location/contact, unstable load, pressure drop across distributor. | Relocate/secure sensing bulb, investigate system load stability, check distributor. |
7. Specifications
| Attribute | Value |
|---|---|
| Brand | Danfoss |
| Model Number | 067N9209 |
| Item Weight | 2.6 pounds |
| Product Dimensions (L x W x H) | 5.25 x 4.25 x 3.25 inches |
| Inlet Connection Type | Outside Diameter Flared |
| Refrigerant Compatibility | R410A |
| Date First Available | April 1, 2019 |
8. Warranty and Support
Danfoss products are manufactured to high-quality standards and are typically covered by a limited warranty against defects in materials and workmanship. For specific warranty terms and conditions, please refer to the documentation provided with your purchase or visit the official Danfoss website.
For technical support, troubleshooting assistance, or to inquire about replacement parts, please contact Danfoss customer service or an authorized Danfoss distributor in your region. When contacting support, please have your product model number (067N9209) and purchase information readily available.
Danfoss Official Website: www.danfoss.com
