What Is a Refrigeration Vacuum Pump?

Evacuation is an indispensable and important process in the production or maintenance of refrigeration equipment before charging refrigerant. That is, a vacuum pump is connected to the refrigeration system pipeline (generally the high and low pressure sides are connected at the same time), and the non-condensable gas and moisture in the system pipeline are excluded. ^[1]

Remove the system

The operation of evacuating the refrigeration system should be performed after the system is cleaned, drained and leak tested. Evacuation can not only further check the system's air tightness, but also exclude air, moisture and other non-condensable gases from the system, and prepare the system for refrigerant charging.

Evacuation should be performed by a vacuum pump (Figure 1). For small refrigeration systems using medium, small open, semi-hermetic compressors, the system's own compressor can be used to pump air without a vacuum pump (see Figure 2) Except that the use of this machine is prohibited in the product instruction manual provided by the equipment manufacturer.

Operation method and steps for vacuuming by vacuum pump

During the use of the vacuum pump, you should pay attention to:

(1) A valve should be installed on the pump inlet pipeline, and the valve should be closed before the pump is stopped. It is best to install an automatic check valve.

(2) The diameter of the pipeline connecting the pumped container should not be less than the diameter of the air inlet of the pump, and the pipeline and the elbow should be short and small respectively; pay attention to the leakage of the pipeline.

(3) Focus on checking the oil level before each start, and it is advisable to fill the oil to the center of the oil level when stopping the pump.

(4) When the pump is not in use, use rubber caps to plug the intake and exhaust ports to prevent dirt from entering the pump.

(5) When connecting the power supply, the wiring should be in accordance with the specifications on the motor label. Note that the direction of rotation of the motor must be consistent with the direction of the arrow on the support.