Nitrogen pressure testing acts as a "safety gate" before a cold storage refrigeration system is put into operation, directly impacting the sealing integrity of the refrigerant and the safety of stored goods. A common issue during installation is the omission of this critical step—skipping the 24-hour nitrogen pressure test at the standard 1.8 MPa and proceeding directly to charging refrigerant. While this may seem to save construction time, it allows hidden risks such as weld leaks to go undetected. By the time a refrigerant leak becomes apparent, significant cargo losses have often already occurred.

           The core value of nitrogen pressure testing lies in its ability to detect leaks in advance. Nitrogen is chemically stable, non-corrosive, and cost-effective, making it ideal for simulating the operating pressure of the refrigeration system. The 1.8 MPa testing standard far exceeds the system’s normal working pressure, enabling precise detection of hidden issues like micro-cracks in welds or faulty valve seals. If refrigerant is charged directly without testing, initial leaks may be slow and subtle due to lower pressure, making them difficult to detect with conventional methods. Refrigerant can leak silently until the system fails to cool effectively. The cost of skipping pressure testing goes beyond refrigerant loss. Refrigerant leakage reduces the unit’s cooling capacity, causing the storage temperature to rise gradually. 

           This puts perishable goods like fresh produce and frozen items at risk of spoilage. Additionally, insufficient refrigerant can lead to inadequate compressor lubrication, accelerating wear, shortening equipment lifespan, and resulting in repair costs that can amount to thousands. In contrast, a 24-hour nitrogen pressure test ensures system integrity through stable pressure gauge readings. If a leak is detected, it can be repaired promptly by re-welding, preventing more significant losses later. The pressure testing process must follow a standardized procedure: First, fill the system with nitrogen to 1.8 MPa, then close the valves and let it stand for 24 hours, recording the pressure every 6 hours. If the pressure drop exceeds 0.05 MPa, apply soapy water to weld joints, valves, and other critical areas. Bubbles will indicate leak points, which should be re-welded before repeating the pressure test until it meets the standard. Once the test is passed, the system must be vacuumed to remove air and moisture before refrigerant charging begins. 

         The installation of a cold storage refrigeration system cannot afford simplified procedures. Nitrogen pressure testing is not an "option" but a "necessity." Spending an extra day upfront to conduct a proper pressure test can effectively prevent a chain of risks, including refrigerant leaks, cargo losses, and equipment damage. Adhering to this standard is essential to building a strong first line of defense for the stable operation of cold storage and the safety of stored goods.