Pump Health Check

Fig. 1 Health Check · pump 180-1422 Hover an impeller · arrows pick a stage —

Pump failure risk0%

Normal—

NormalWatchPre-repairFailure

impellers, wear within limits seal wear wear at limit diffusers cut plane water cavitation leakage through the seal

Head curve H(Q) and efficiency—

Health Check verdict

Operating point——

Pump efficiency——

NPSH margin——

Until repair——

Discharge P · 90 d actual + forecastd

Pump conditionsinput

Flow rate Q

Suction pressure Ps

Motor frequency

Wear ring clearance relative to rated, averaged over stages

Water temperature

Wear rate clearance growth from vibration and flow data over 90 d

Demonstration model of a 180-1422 multistage pump: 8 stages of 178 m at 180 m³/h and 2,950 rpm, stage efficiency up to 75 %, water ρ = 1.05 t/m³, required header pressure 140 atm, required NPSH 12 m at rated flow. Wear ring clearance grows towards the discharge side; leakage through the clearance grows as the clearance to the power of 1.5. The repair limit is a clearance of ×2.5 or discharge pressure below required. In the product, the characteristics come from the pump datasheet and bench tests.