Used Gram Screw Compressors

Inspect service records, operating hours, oil analysis results, rotor and housing wear, seals, and control panels. Verify refrigerant compatibility, test-run under load if possible, and check for signs of overheating or oil contamination.

Match cooling capacity (kW/RT), suction and discharge pressures, and expected duty cycle. Allow margin for peak loads and consider VFDs to optimize part-load efficiency.

Oil-injected compressors are more efficient and robust for larger systems but require oil management and separation. Oil-free is cleaner for sensitive applications but usually higher cost and lower tolerance for contaminants.

Secure rotors and shaft positions, drain and tag oil lines, protect controls and electrical components, and use heavy-duty crating or skid with vibration padding. Work with carriers experienced in heavy refrigeration equipment and insure transit.

Regular oil and filter changes, oil analysis, checking separator and cooler condition, verifying valve function, monitoring vibration and bearing temperatures, and following manufacturer inspection intervals.