How often should I replace a marine pump impeller?

Inspect at every overhaul (typically every 5 years for centrifugal pumps). Replace when erosion exceeds 0.5 mm or imbalance exceeds the OEM balance class. Simsite® composite impellers can run 25+ years without replacement in seawater service.

When does a mechanical seal need replacing?

Standard practice is 2.5–3 years or 20,000 running hours, whichever comes first. Replace immediately on visible leakage or hot spots.

Can MARITECH supply complete overhaul kits?

Yes — MARITECH ships complete overhaul kits (seals, wear rings, bearings, gaskets, fasteners) for Allweiler, IMO, Naniwa and Heishin pumps from Hamburg stock or to order.

Marine pump overhaul intervals: when to replace impellers, seals and bearings

For most marine centrifugal pumps the practical overhaul interval is 5 years (or one special survey), with mechanical seals and wear rings replaced at half that. Screw and gear pumps tolerate longer intervals if oil cleanliness is maintained. Below is field-based guidance MARITECH gives Hamburg-based fleet operators.

Typical mechanical seal life (centrifugal, seawater): 20,000 h
Special survey interval (most class societies): 5 years
Screw pump life with 10 µm filtration: 30,000+ h

Centrifugal pumps

Mechanical seals: 2.5–3 years or 20,000 running hours. Wear rings: 5 years or at every special survey. Impeller: inspect at every overhaul, replace when erosion exceeds 0.5 mm or when imbalance exceeds the OEM balance class. Bearings: replace on condition (vibration trend) or at 5 years.

Twin-screw and triple-screw pumps

If the pumped fluid is clean lube or fuel oil and filtration is maintained at 10 µm absolute, screw sets reach 30,000+ hours. Mechanical seal replacement still recommended at 5 years.

Gear pumps

Internal-gear and external-gear pumps in fuel-oil service: gear set inspection at 3 years, replacement on condition. Bushings replaced at every overhaul as standard practice.

Class-society alignment

DNV, Lloyd's Register and BV align overhaul windows with the 5-year special survey. Continuous-machinery surveys allow staggered overhauls — discuss with your class surveyor.

Marine pump overhaul intervals: when to replace impellers, seals and bearings

Centrifugal pumps

Twin-screw and triple-screw pumps

Gear pumps

Class-society alignment

Frequently asked questions

Sources

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