- Determine whether you need to increase or decrease the temperature reading on the thermostatic expansion valve.
- Locate the adjustment needle on the thermostatic expansion valve.
- Turn the adjustment needle one quarter turn counterclockwise to decrease the temperature. Each quarter turn is equal to one degree.
- Turn the adjustment needle a quarter turn clockwise for each degree needed, to increase the temperature.
Do I need to adjust my sporlan expansion valve?
Expansion Valve Adjustment Each Sporlan TEV is thoroughly tested and set at the factory before shipment. This factory superheat setting will be correct and no further adjustment is required for the majority of applications. However, there are many factors which can affect the performance of a TEV.
How does a sporlan TeV thermostatic valve work?
The thermostatic element on all standard Sporlan TEVs is replaceable. The diaphragm is the actuating member of the valve. Its motion is transmitted to the pin and pin carrier assem- bly by means of one or two pushrods, allowing the pin to move in and out of the valve port.
How do you adjust the temperature on a thermostatic expansion valve?
Locate the adjustment needle on the thermostatic expansion valve. Turn the adjustment needle one quarter turn counterclockwise to decrease the temperature. Each quarter turn is equal to one degree. Turn the adjustment needle a quarter turn clockwise for each degree needed, to increase the temperature.
What is the maximum temperature allowed in a sporlan valve?
On L, C, Z, and X charges, 250°F maximum valve body temperature is permissible if the bulb temperaturedoes not exceed those shown in the table. Expansion Valve Adjustment Each Sporlan TEV is thoroughly tested and set at the factory before shipment.
How do you adjust a thermostatic expansion valve?
The TXV cannot be adjusted open or closed, it is a modulating valve. Turning the adjustment stem clockwise will only increase spring pressure causing a higher superheat. Turning the adjustment stem counterclockwise will decrease spring pressure reducing superheat.
How can I reduce superheat?
Valve setting Turning the adjusting screw clockwise will increase the static superheat. Conversely, turning the adjusting screw counterclockwise will decrease the superheat.
How do you adjust the expansion valve on a marine refrigeration system?
The superheat setting of most thermostatic expansion valves is adjustable. Remove the seal cap on the valve and turn the adjusting stem with a screwdriver. Turning the stem to the right increases the spring pressure, reducing refrigerant flow and thus increasing superheat.
What should the expansion valve superheat setting?
Expansion valves are often suspected of causing system problems. But generally speaking, a TEV is operating properly if it maintains superheat of 5° to 15°. If superheat is low (lower than 5°), there is a potential for flooding refrigerant back to the compressor.
How do you adjust superheat on sporlan TXV?
What's Your Superheat? To reduce the superheat, turn the adjusting stem counter-clockwise. To increase the superheat, turn the adjusting stem clockwise. When adjusting the valve, make no more than one turn of the stem at a time and observe the change in superheat closely to prevent over-shooting the desired setting.
What happens if superheat is too high?
Too high of a superheat can cause the heat of compression to increase, causing the temperature at the discharge valves to increase. If the temperature increases beyond its safe operating temperature, it will cause damage to the compressor.
How do you adjust subcooling?
The temperature that you read with the thermometer should be lower than the saturated condensing temperature. The difference between the measured liquid line temperature and the saturated condensing temperature is the liquid subcooling. Add refrigerant to increase subcooling. Recover refrigerant to reduce subcooling.
What two pressures control the operation of an automatic expansion valve?
What two pressures control the operation of an automatic expansion valve? Spring and evaporator pressures.
What is thermostatic expansion valve superheat?
A thermostatic expansion valve (TXV) (see Figure 1) is a refrigeration and air conditioning throttling device that controls the amount of refrigerant liquid injected into a system's evaporator—based on the evaporator outlet temperature and pressure—called the superheat.
What is the problem when the evaporator superheat reading is too low?
A low or zero superheat reading indicates that the refrigerant did not pick up enough heat in the evaporator to completely boil into a vapor. Liquid refrigerant drawn into the compressor typically causes slugging, which can damage the compressor valves and/or internal mechanical components.
Do you check superheat or subcooling for TXV?
If the metering device is a fixed orifice such as a piston or capillary tube, the refrigerant charge of the system can be checked with Total Superheat. If the metering device is a TXV then the refrigerant charge can be checked with Subcooling.
What causes high superheat?
Excessive or high superheat is an indication of insufficient refrigerant in the evaporator coil for the heat load present. This could mean that not enough refrigerant is entering the coil or this could also indicate an excessive amount of heat load on the evaporator coil.
Why is my expansion valve freezing?
THE CAUSE MAY BE:1. Moisture — Water or a mixture of water and oil frozen in the valve port or working parts of the valve will prevent proper operation. This is a common source of trouble on expansion valves. Since the valve is the first cold spot in the system, moisture will freeze and block the valve open, closed, or any position in between. If the valve is frozen in the intermediate position so that flow is restricted, the superheat will be high.
Why are TEV valves needlessly replaced?
As a result, many valves are needlessly replaced when the cause of the system malfunction is not immediately recognized.
Do you need to disassemble a solder valve?
It is not necessary to disassemble solder type valves when soldering to the connecting lines. Any of the commonly used types of solders, e.g., 95-5, Sil-Fos, Easy-Flo, Phos-Copper, Stay Brite 8 or equivalents may be used for copper to copper connections. When soldering a brass refrigerant distributor to the valve, appropriate solders for these connections, such as 95-5, Easy-Flo, Stay Brite 8 or equivalents must be used. It is important however, regardless of the solder used, to direct the flame away from the valve body and avoid excessive heat on the diaphragm, Figure 2. As an extra precaution, a wet cloth may be wrapped around the body and element during the soldering operation.