Refrigerant Recovery, Charging and Leak Testing Procedure

Purpose. This procedure describes how technicians recover, evacuate, charge and leak test refrigerant systems safely and record each step in the refrigerant handling log.

1.Preparation

Confirm the refrigerant type from the system nameplate and the customer record, check the safety data sheet, and confirm the technician's licence covers the refrigerant and system. Select the recovery unit, cylinder, scales, manifold gauges and leak detector from the instrument register and confirm they are within calibration or service. Isolate electrical supply to the system following the safe isolation procedure where the work requires it.

2.Recovery

Weigh the recovery cylinder before starting and never exceed eighty percent of its rated capacity. Connect the recovery unit, recover liquid then vapour, and continue until the system reaches the required vacuum. Record the recovered mass in the log.

3.Pressure test and evacuation

Pressure test with dry nitrogen to the specified test pressure and hold for the required period, checking joints with a leak detection solution. Release the nitrogen safely, then evacuate with a vacuum pump to the specified level and confirm the vacuum holds.

4.Charging

Charge by mass to the nameplate or calculated charge using calibrated scales, or by superheat and subcooling where the system requires. Record the charged mass and the cylinder used. Never mix refrigerants in a system or a cylinder.

5.Leak testing and commissioning

Leak test all joints with an electronic detector suited to the refrigerant after charging. Run the system and record suction and discharge pressures, superheat, subcooling, temperatures and current draw on the commissioning sheet. Confirm the cold room or cabinet reaches set point.

• Electronic leak test of every joint
• Operating pressures and temperatures recorded
• Compressor current checked against nameplate
• Set point and pull down confirmed

6.Records

Complete the refrigerant handling log entry before leaving site. Return recovery cylinders to the workshop for reconciliation and reclamation.