Copper pipe welding defects are the primary cause of refrigerant leaks. Uncontrolled temperatures during welding can burn through the pipe wall, creating visible leak points. Substituting ordinary brass solder rods for silver solder rods containing 35% silver can lead to brittle joints with poor low-temperature crack resistance, causing the welds to contract and crack in low winter temperatures, resulting in hidden refrigerant leaks. Refrigerant leakage not only increases refilling costs but also forces the unit to operate under high loads due to insufficient refrigerant, accelerating compressor wear.

          Omitting nitrogen pressure testing allows potential leak points to remain hidden. Standards require a nitrogen pressure test of 1.8 MPa for 24 hours before refrigerant filling to identify hidden leaks at welds, valves, and other critical points. Direct refrigerant filling makes it difficult to detect minor leaks initially. By the time a leak becomes apparent, the cold storage may already experience a sudden drop in cooling capacity, uncontrolled internal temperatures, and a significantly increased risk of goods spoilage.

Substituting insulation materials leads to insulation failure. Replacing polyurethane boards with EPS foam boards doubles the thermal conductivity, failing to effectively block heat exchange between the interior and exterior. This causes significant cold loss from the storage chamber, forcing the refrigeration unit to start and stop frequently to maintain temperatures, which significantly increases power consumption. It also leads to temperature fluctuations, disrupting the storage environment for goods, particularly posing severe risks to fresh produce and pharmaceuticals that require constant temperature storage.

          The construction of refrigeration systems must adhere to full-process standards: use silver solder rods containing 35% silver for welding and precisely control flame temperatures; strictly perform nitrogen pressure testing to ensure no leaks; select qualified polyurethane insulation materials and ensure proper seam sealing. While standardized construction may seem to increase initial investment, it effectively avoids risks such as refrigerant leaks and cooling failures, building a solid core defense for the stable operation of cold storage facilities.