Even with no moving parts, the capillary tube will vary flow rate as system pressures change in the evaporator, in the condenser, or both. In fact, it can only reach its best efficiency a… See more

If the cap tube's resistance is too great because the tube is too long, we say that a partial restriction exists. Also, if the diameter is too small or there are too many turns as it i… See more

The capillary tube simply does not have a feedback mechanism like a TEV remote bulb to tell the metering device that it is running high superheat. This can cause the system to r… See more

The system will now have a normal evaporator superheat of about 10 degrees to 12 degrees. These normal readings will only occur with low heat loads on the evaporator… See more