While our customers are wholesalers, Packard knows that you, the contractor, have a choice. You are often presented with many buying options, and being well-informed about your purchase can help make your job easier and more successful.
This is why we have dedicated a section of our site for contractors. In this section, you will find helpful product tips, tools and some clips from our training classes. We’ve also provided a distributor locator so you can find the nearest wholesaler who can give you access to Packard products.
For proper operation, the thermostatic expansion valve must be installed properly!
The thermostatic expansion valve (TXV) is a metering device that controls the flow of refrigerant in the refrigeration or A/C system. Its purpose is to see that the proper amount of refrigerant is present based on the demand upon the system. When properly installed, the TXV assures that superheat is present in the system. This results in the refrigerant returning to the compressor through the suction line being in a vapor state. If the refrigerant returning to the compressor is in a liquid state, rather than a vapor, compressor failure can occur.
Among the key components of the TXV are the valve body and a sensing bulb connected by a capillary tube. The valve body is installed to the liquid line before the entrance to the evaporator coil. At the top of the valve body is a valve head. The valve head, capillary tube, and sensing bulb contain a refrigerant, which is charged during the TXV manufacturing process. The bulb senses the temperature of the refrigerant at the point where it is attached.
The sensing bulb is mounted horizontally to the suction line after the exit from the evaporator coil. The bulb should not be mounted at the bottom of the line. This is to avoid an inaccurate reading of the temperature of the refrigerant because of the presence of oil in the bottom of the line. If it is not possible to mount the bulb horizontally, it can be mounted vertically, but the point where the capillary tube exits the bulb must be facing up. The bulb must be attached with a metal mounting strap to assure maximum contact between the bulb and the suction line, allowing for more accurate temperature readings. The bulb should then be entirely covered with insulating tape to avoid any influence of ambient temperature around the bulb.
The bulb senses the temperature of the refrigerant as it leaves the evaporator. Demand on the system will cause temperature changes of the refrigerant in the system. These changes in temperature will be sensed by the bulb. A temperature change sensed by the bulb will result in a temperature change to the refrigerant charge in the TXV. If demand for cooling is high, the temperature of the refrigerant charge increases in the TXV, and increased pressure in the valve body will occur. The TXV will release more refrigerant into the system. If demand for cooling is low, the temperature of the refrigerant charge decreases in the TXV, and decreased pressure in the valve body will result. The TXV will reduce the flow of refrigerant in the system.
The TXV is a remarkable device that can provide stable performance as conditions change. By following installation instructions precisely, it will provide years of trouble-free operation.
Packard has developed a complete HVACR critical components training program, which has received approval by North American Training Excellence (NATE) - the leading certification program for HVACR technician, and the only test approved by the entire industry. Below are some video excerpts from our instructor led training courses which we hold at Wholesaler locations nationwide.
|Let us Help|
|Service||800 – 334 – 1769|
|Local||770 – 427 – 5765|
|Fax||770 – 427 – 5140|