3D Series (12+ sizes: 106-400)

Verify pressure relief valve opens at or above minimum threshold (minimum 10.3 bar/150 PSI per DNV rules) under load; test response time and set point stability with pressure gauge

Inspect shaft seal condition (Carbon/Silicon Carbide or Silicon Carbide types per model); verify no visible oil weeping at bearing or seal interface; measure seal face runout; replace if wear grooves exceed manufacturer limits

Visual inspection of pump casing interior and rotor surfaces for pitting, erosion, or stress corrosion cracking; measure casing wall thickness if previous damage suspected; check rotor hardness (alloy steel nitride hardened per 3D/6D/12D specs)

Measure inlet/discharge pressure differential; verify rotor-to-casing clearances; check bearing preload and alignment; test operating noise at rated speed; assess pump mounting (foot vs. flange) and foundation rigidity

Confirm operating fluid viscosity within range (2-3800 mm²/s for ACF; 2-5000 cSt with approval for LPQ); verify temperature does not exceed limits (90°C ACF, 130°C ACE); check for deposits or sludge formation in pump case