In large industrial refrigeration and air conditioning systems, Pressure Safety Valves (PSVs) are essential for protecting both high-pressure and low-pressure lines, ensuring safe operation and the integrity of the entire system.
High-Pressure Line: This line carries compressed refrigerant to condensers and other system sections. Overpressure here (often >30 bar) may cause severe damage, including pipe rupture or compressor failure. PSVs are installed after compressors or on liquid receivers to automatically release excess refrigerant and prevent catastrophic failure.
Low-Pressure Line: This line leads to evaporators where the refrigerant absorbs heat. Failures in expansion or evacuation systems can raise pressure, damaging components. PSVs installed on gas lines protect the system by releasing excess pressure automatically.
To avoid unnecessary activations, PSVs are set with a positive margin of +3% above nominal set point, compliant with ISO 4126, ASME, and PED standards. This ensures activation only during real emergencies, improves system stability, and reduces maintenance.
