W Series Twin-Screw Pumps (W2-W10, e.g. W5.1k-65, W5.2z-87, W7, W9.5zk)

Verify oil color (should be clear amber to brown, not black/opaque), viscosity grade verification via viscosity index testing, acid number (TAN) measurement, and iron/wear particle content via ferrography analysis per ASTM D6595. Check oil circulation temperature stability (typical 40-60°C).

Inspect suction strainer mesh for debris accumulation, verify positive suction pressure (vacuum reading <50 mbar), check suction line for air leaks via bubble test, confirm strainer bypass valve operation and differential pressure gauge (change when >0.2 bar).

For HP/W/V/U/T series: verify clean lube oil is circulating through external bearings and timing gears, check bearing temperature (should remain <80°C), inspect for oil leakage at bearing seals, confirm timing gear mesh is visible and properly submerged in oil reservoir.

Measure seal leakage rate (target: <0.1 ml/hour for API Plan 53A, <0.5 ml/h for standard seals), inspect seal faces for wear/scoring via magnifying glass, monitor seal chamber temperature (max 80°C), verify cooling/flushing plan integrity if fitted (e.g., API Plan 53B), check seal flush line for blockage.

Monitor discharge pressure pulsation (should be <5% ripple for W/V series), measure actual pump displacement via volumetric test and compare to baseline, inspect for metal particles in discharge line filter, perform thermography on pump casing to detect internal friction hotspots (normal: casing ~45-60°C, alarm >70°C).