Learning chapter
Pumps
The complete pump series: how pumps work, construction, suction and NPSH, performance curves, watchkeeping, pumping systems, troubleshooting, overhaul and safety.
This chapter collects 11 illustrated lessons on Pumps as part of Auxiliary Machinery & Shipboard Systems, ordered as they are best studied. It opens with Pump Principles and Pump Types, Centrifugal Pump Construction, Axial Thrust Balancing & Balance Holes in Centrifugal Pumps, Suction, NPSH, Cavitation and Priming, Pump Curves and Speed Rules Made Simple, Operation and Watchkeeping and 5 more. Each lesson is written for MEO oral and written preparation: definitions first, then how the system behaves, then the checks and figures used in practice.
Explore the lessons
01
Pump Principles and Pump TypesHow pumps work and the two families that decide everything: centrifugal, axial, reciprocating, gear and screw — and where each type is used.
02
Centrifugal Pump ConstructionCentrifugal pump anatomy: casing types, wear rings and clearances, shaft and bearings, gland packing, mechanical and labyrinth seals.
03
Axial Thrust Balancing & Balance Holes in Centrifugal PumpsMaster axial thrust balancing in centrifugal pumps: pressure distribution on impeller shrouds, balance holes and back wearing rings, pump-out vanes, balance drums, and balance discs.
04
Suction, NPSH, Cavitation and PrimingWhy the suction side fails: suction lift limits, NPSH available vs required, cavitation damage, air ingress, priming methods and suction piping rules.
05
Pump Curves and Speed Rules Made SimpleSimple explanation of pump H-Q curve, BEP, affinity laws, TDH and operating point for marine engineers.
06
Operation and WatchkeepingRunning pumps: pre-start checks, starting centrifugal and positive displacement pumps, running rounds, flow control and planned maintenance.
07
Pumping Systems OnboardShipboard pumping systems: bilge and ballast, fire and emergency pumps, sea water circulating, cargo, fuel oil, oily water separator and feed water.
08
Troubleshooting IndexPump troubleshooting by symptom: no delivery, low capacity, lost suction, cavitation, vibration and overload — causes, action and prevention.
09
Overhaul, Inspection and RepairPump overhaul step by step: isolation, dismantling, clearances, reassembly, alignment, packing and seal fitting, repair limits and testing.
10
Safety and Emergency ActionsPump work hazards, isolation and lock-out, emergency actions for lost suction, cavitation, overheating, seal failure and fire, plus safety rules.
11
Positive Displacement Pumps (Screw, Gear, Reciprocating) & Jet EductorsMaster marine positive displacement pumps: triple-screw IMO pumps, external gear pumps, Mono cavity pumps, reciprocating pumps, and jet eductors for MEO Class 4 & 2 examinations.