This meter is a very popular view. It is used in both refrigeration equipment, commercial and residential air conditioning equipment, both residential and commercial. A small, copper pipes in the size of its I.D. (inner diameter). The liquid line of the condensing unit can be Vi-inch copper tubing. When he enters the evaporator section liquid line limits down to the capillary tube with I.D. may .065 inches. Limiting refrigerant, increase the pressure on the high side of the system. The length of the pipe is also relevant to the pressure. You can see that this system has a fixed metering device. If a large heat load imposed on this type of device, it takes a long time to remove the heat load. You can see that the thermostatic expansion valve much better respond to changes in heat load. Capillary tube system works well in the house of units, refrigeration and air-conditioning. Fig. 15-14 shows the typical capillary tube systems. Care must be taken to protect the inside of the pipes from becoming restricted. This is the reason for the fine strainer at the inlet of the pipe. All foreign bodies should be locked up here and contains.