Vacuum, Charging and Recovery Sugiyanto, S.T., M.Eng.

Review : Refrigerant Refrigerants are substances that are used to absorb and transport heat for the purpose of cooling. The most common refrigerants used in mechanical refrigeration systems today are Refrigerant- 123 (or R-123), R-134a, and R-22. Ammonia (R-717) and, under certain operating pressures, even water (R-718) and carbon dioxide (R-744) can be used a refrigerants

Classification of fluids used as refrigerants

Refrigerant cylinder

Review : Effect of Transferring Heat SENSIBLE HEAT LATEN HEAT

Review : Refrigeration Systems

Review : Basic Refrigeration Systems

Heat of vaporization of water Refrigeration cycle

Refrigeration Cycle

Heat of compresion

Expansion Device

Vacuum and Charging Equipments

Refrigerant Recovery Equipment

Gauge manifold

Portable charging cylinder and digital scale

Gauge manifold used with vacuum pump

Component part for a general unit used for evacuating and charging a systems A.Charging Cylinder B.Vacuum pump C.Gauge manifold D.Pressure tube adaptor

Connecting of gauge manifold A.Some systems have both a suction seflice valve and a discharge seryice valve. B.Some havi a suchon semce valve adaptor mounted on the comprcssor C.Some do not have any service vatves, but do have a process tube D.Some have a process tube that is too short or inaccessible. In such systems, a piercing valve is used. It is attached to either the liquid line, the suction line, or both.

The most popular way to purge the service line When connecting refrigerant lines or gauge manifold to any refrigerating system, keep the system clean. The lines, gauges, and manifold must be free of dirt, moisture, and air. The manifold should be purged with the same refrigerant used in the system. The manifold and connecting lines must be purged before the system service valve is opened. They must also be purged before using a piercing valve stem to open the tubing. Loosen the line fitting on the system service valve at C, then open valve B. Open cylinder line valve E just a little. Repeat the same procedure for valves D, A, and E. The cylinder refrigerant will purge all the lines and the manifold of air and moisture.

Service Valve

Service valve mounted on hermetic system may be used for many purposes To check internal pressure To discharge the system or add refrigerant To add oil To evacuate the system To make it easier to replace driers, motor compressor, evaporator and refrigerant controls To recharge the system

Three types of piercing valves A.Charge-and tap valve. B.Hand valve type C.Line-tap type with hexagonal wrench

Adding oil to the system

Recovery

Vacuum

Triple Evacuation Process

Low Side Charging

High Side Charging

The following step use charging cylinder

References Althouse, Andrew Daniel, 2004, Modern Refrigeration and Air Conditioning, The Goodheart-Willcox Company Inc, USA ,2000, A Trane Air Conditioning Clinic, American Standard Inc, USA