Capillary Tube and Selection

Capillary tube is selected according to the capacity of the condenser system positioned between the evaporator and the inner diameter ranging between 0.76 and 2.16 mm is often very small diameter pipe.

Capillary tube inner diameter is very small because the name is given. There are essentially two tasks.reducing the pressure of the fluid in the fluid from the condenser case and measuring the amount (the required amount) reaches the evaporator. When the compressor is seeing a bridge between low and high pressure fluid circuit allows the switching to the low side of the high pressure side. Thus the pressure is equal on both circuits (balancing event) and the compressor is not met with again from a large pressure load while. Capillary tube best cooling the load is less stable and, freezers and even housing-related and small, used in commercial air conditioning systems. If the system is required to operate in a wide range of load; The refrigerant pressure drop and volume control should be made more appropriately. In this case the proposed device is a thermostatic expansion valve.

Advantages of Using Capillary Tube

Capillary reducing the cost of the main objectives in the development of the use of pipe materials has been to reduce the sale price. The second reason is to reduce the starting torque capillary tube in use. These benefits occur when circulation. When starting the compressor circulation, it will make a move against the compressor pressure difference occurs and additional starting torque is needed.

Disadvantages of Using Capillary Tube

There is no ability to adjust the capillary flow of the refrigerant pipe. Therefore, the load on the unit or decreases, the number increased system efficiency, compared to systems using a thermostatic expansion valve indicates a larger decline. cycle stops, the unit door does not stop the flow of refrigerant pipes. This compressor is an advantage for starting torque requirement, but may be disadvantageous for the mechanical lifetime of the compressor. The amount of refrigerant in the system can shorten the life of the compressor seriously.

Capillary Tube Replacement

Cooler also used capillary tube is damaged, replace it with a capillary tube having an inner diameter and the same length as the original. To replace the pipes with different length or size.

Capillary Tube (Capillary Tube) Selection

For the following reasons, widely used as a tool in the expansion of capillaries small refrigeration applications. Features:

– Easy to understand
– Lower costs
– Reliability: No joint part
– Normal operation compressors used as a pressure-equalizing before running again.

However, it can affect all parts of the applications and performance can not be known, it remains a sensitive selection process. If the main elements of the installation compressor, evaporator,condenser is to be achieved with limited applications and operating conditions requires a physical expansion means the number of parameters to meet. Capillary tube evaporator must allow a certain flow of gas and the main parameter for determining that:

– Evaporation heat
– Condensing temperature
– Capillary liquid sub-cooling heat entering

These parameters vary depending on the operating conditions. Continuous operation, “on / off operation”, “start-up” selection of a capillary tube to optimize performance at low power consumption, the situation is very difficult. Therefore, the selection will always form a compromise between these parameters. Capillary tube selection can not be based on a precise mathematical formula. Suitable for use in the following diameters:

-0.8 mm
-1.0 mm
-1.2 mm
-1.5 mm
-2.0 mm
-2 × 1.2 mm
-2 × 1.5 mm

Sometimes, an intermediate diameter is clear that better results (eg. 1 to × 1.2 mm). In these cases, intermediate capillary length of about ‘inch’ calculated as. It is recommended that not too long or too short capillary selected. The ideal length is between 2.5 m and 1.5 m. It increases the risk of a short capillary tube deflection. The long capillary tube (except some cases), particularly in short-cycle system will lead to excessive pressure and can not benefit from the change in the operating conditions by synchronizing the time. This is also built around operating conditions, causing a longer time to be reached. In all cases, capillary length must never exceed five thousand times the inner diameter of the capillary. The importance of the gas filling the capillary system is not connected to his choice. Less filling leads to lower operating temperatures and reduces the cooling capacity. More filling high discharge pressure, compressor over-filling compressor toward transporting liquid, freeze and cause cooling capacity as a result of the reduction in the evaporator.

Capillary Tube Fitting

the maximum attention during the show capillary tube assembly is required. Because the diameter of the capillary tube as the term implies, especially very small internal diameter of the copper pipe. Too much bend blockage due to the small inner diameter or cracking during bending and twisting of the place, there may be problems such as breakage.

Would become worn or that the capillary tube has no moving parts that need to be changed, because the small diameter of the appropriate length is designed to carry on the refrigeration load is a pipe made of copper. Repair of the capillary tube is not in question, it must be replaced with new ones. During the replacement process should be fluid refrigerant in the system. Plugged capillaries with an output drayer replacing it with a new evaporator is made from a mark near the entry point and by removal of cut copper pipe cutting tool or side cutters. We should not try to change the capillary tube within the system to change the length or size. We need to determine what happened before changing the inner diameter of the capillary tube. What matters is that the physical length of the insert to be the most accurate method is to leave at least 2.5 cm from both ends. Capillary tube, in the same length as the original, and we must change with a capillary pipe of the same size.