Cargo Pump (Centrifugal, Pumproom)
A pumproom-mounted centrifugal cargo pump keeps its driver -- steam turbine or electric motor -- outside the hazardous space, coupled to the impeller through a long vertical line shaft that crosses the pumproom bulkhead through a sealed gland.
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What sets this pump apart
A pumproom centrifugal cargo pump is driven from outside the hazardous space: the impeller sits low in the pumproom, but the steam turbine or electric motor that turns it sits in the engine room, connected through a long vertical shaft that passes through a gas-tight bulkhead gland. That single arrangement separates it from a deepwell pump, where the motor rides on top of the column inside the tank, and from a submersible pump, where the whole unit is immersed in the cargo. The bulkhead penetration gives easier maintenance access to the driver but adds one more sealing point that can pass vapour into the engine room if it is neglected.
Main components
Casing and impeller
Single or multi-stage centrifugal casing, usually duplex or austenitic stainless steel for corrosive or aggressive cargoes, carbon steel with a protective coating for cleaner products. Impeller trim (diameter and vane profile) sets the duty point on the pump curve.
Vertical line shaft and bearings
A long shaft, supported by intermediate line shaft bearings, connects the driver to the pump. Bearings are usually product- or water-lubricated and are the first place misalignment shows up as vibration.
Bulkhead gland
The seal where the shaft crosses from pumproom to engine room, either a mechanical seal or a packed gland. This is a designated gas-hazard boundary and is monitored accordingly.
Driver
Steam turbine, common on older and larger tankers because it needs no electrical certification in the pumproom, or a variable-speed electric motor located in a non-hazardous area, coupled through the same vertical shaft.
Suction bell and strum box
Strainer at the tank suction that keeps debris and scale out of the impeller. Stripping arrangements, eductors or a dedicated stripping pump, handle the last cargo the main pump cannot lift once suction breaks.
Selection and sizing
Sizing runs off capacity, typically several hundred to well over a thousand cubic metres per hour per pump on a product or crude tanker, total developed head against manifold back-pressure and shore line resistance, and NPSH available at minimum tank level versus NPSH required by the pump. That last figure usually limits how far a tank can be stripped by the main pump before switching to eductors. Cargo viscosity and vapour pressure at loading temperature also set limits: a viscous or high-vapour-pressure cargo needs a flatter curve and more NPSH margin than the pump's water-test curve suggests. Most tankers fit one pump per cargo tank group so segregated grades can be discharged in parallel.
Regulations and class
The pumproom is a hazardous space under SOLAS Ch. II-2 and, where applicable, the IBC Code, with mechanical ventilation running continuously in port and gas detection at the entrance and at the bulkhead gland. Class rules require periodic survey of the shaft seal and bearings, and the bulkhead penetration is a specific item on annual and special survey checklists. Electric motor drivers in the engine room must still satisfy the certification appropriate to their proximity to the hazardous boundary.
Typical faults
- Bulkhead gland wear -- loses its seal over time; the consequence is vapour migration into the engine room, which is why gas detection sits right at that point.
- Cavitation from insufficient NPSH -- usually from stripping too low a tank level or a blocked strum box; the consequence is impeller and casing erosion and a sharp drop in delivered capacity.
- Line shaft misalignment -- from bearing wear or a shifted foundation; the consequence is vibration that accelerates bearing failure and can eventually crack the shaft.
- Impeller wear from abrasive or corrosive cargo -- the consequence is falling head and capacity even though the pump still runs smoothly.
What to look for in a supplier
- Casing and impeller material actually matched to the cargo slate the vessel trades, not a generic stainless specification.
- A bulkhead seal design with a proven service record and accessible spares.
- Documented pump curves at the viscosities and temperatures the vessel actually loads, not only water curves.
- Line shaft bearing spares available without a long lead time, since a bearing failure can take a pump out of service mid-voyage.
Treat the bulkhead gland like a class item every voyage, not only at survey -- a slow vapour leak there is one of the few cargo pump faults that turns into a safety case rather than a maintenance job.
Typical Manufacturers
3 manufacturers · 25 models
Shinko Industries
15
- Bearing, shaft or guide wear causes vibration, abnormal noise, reduced efficiency or mechanical contact
- Tank-top, shaft or mechanical seal leakage causes visible cargo leakage, vapour release or contamination of adjacent systems
- Hydraulic, electric or mechanical drive faults cause reduced speed, inability to start or protective trips
- Impeller or pump-stage fouling, erosion or damage causes low discharge pressure and reduced cargo rate
- Dry running, poor suction or inadequate tank level causes overheating, vibration or accelerated wear
- High hydraulic efficiency across a wide range of viscosities
- Modular design allows quick coupling replacement during dry‑dock
- Integrated bearing lubrication reduces routine maintenance
- Proven track record on VLCCs and product carriers
- Straightforward wear‑ring clearance inspection at scheduled dry‑docks
- Wear ring clearance can increase if not inspected regularly
- Shaft sleeve erosion reported with abrasive cargoes
- Rubber coupling elements require replacement roughly every four years
- Relatively heavy unit may affect pump‑room layout
- Spare parts availability can be limited in remote ports
- Bearing, shaft or guide wear causes vibration, abnormal noise, reduced efficiency or mechanical contact
- Tank-top, shaft or mechanical seal leakage causes visible cargo leakage, vapour release or contamination of adjacent systems
- Hydraulic, electric or mechanical drive faults cause reduced speed, inability to start or protective trips
- Impeller or pump-stage fouling, erosion or damage causes low discharge pressure and reduced cargo rate
- Dry running, poor suction or inadequate tank level causes overheating, vibration or accelerated wear
- Compact footprint suitable for standard pumproom layouts
- Fixed‑speed electric drive reduces emissions and fuel consumption compared with diesel‑driven pumps
- 200 m³/h capacity matches the flow requirements of many product and chemical tankers
- Shinko’s reputation for robust mechanical seal design simplifies routine inspections
- Mechanical seals can fail if bilge water monitoring is neglected
- Impeller material may corrode or erode with highly aggressive chemicals
- Bearings are prone to overheating without proper lubrication regimes
- Coupling misalignment is a common source of vibration and premature wear
- Bearing, shaft or guide wear causes vibration, abnormal noise, reduced efficiency or mechanical contact
- Tank-top, shaft or mechanical seal leakage causes visible cargo leakage, vapour release or contamination of adjacent systems
- Hydraulic, electric or mechanical drive faults cause reduced speed, inability to start or protective trips
- Impeller or pump-stage fouling, erosion or damage causes low discharge pressure and reduced cargo rate
- Dry running, poor suction or inadequate tank level causes overheating, vibration or accelerated wear
- High flow capacity (≈300 m³/h) suitable for VLCC/Suezmax crude transfers
- Electric drive reduces emissions and eliminates diesel fuel handling on board
- Compact pumproom layout allows easier access for routine inspection
- Proven design for heavy‑oil service with robust impeller geometry
- Historical seal failures can lead to cargo leakage if not monitored closely
- Impeller wear is reported when handling abrasive crude blends
- Motor overload trips may occur under sudden load spikes
- Coupling alignment drift requires periodic realignment checks
- Annual full‑survey downtime adds to maintenance planning
- Mechanical or process fouling caused by cargo residue, corrosion or long service, resulting in reduced transfer, heating, cleaning or vapor-control performance
- Seal, gasket or connection leakage caused by wear, thermal cycling or cargo incompatibility, resulting in cargo or vapor leakage
- Pump, fan, motor or hydraulic drive failure where fitted caused by electrical, lubrication or control faults, resulting in inability to operate or reduced capacity
- Valve, actuator or remote-control failure caused by corrosion, sticking or wiring faults, resulting in incorrect routing or unavailable operation
- Sensor, temperature, pressure or monitoring fault caused by fouling or calibration drift, resulting in implausible readings, alarms or protective shutdown
- Mechanical or process fouling caused by cargo residue, corrosion or long service, resulting in reduced transfer, heating, cleaning or vapor-control performance
- Seal, gasket or connection leakage caused by wear, thermal cycling or cargo incompatibility, resulting in cargo or vapor leakage
- Pump, fan, motor or hydraulic drive failure where fitted caused by electrical, lubrication or control faults, resulting in inability to operate or reduced capacity
- Valve, actuator or remote-control failure caused by corrosion, sticking or wiring faults, resulting in incorrect routing or unavailable operation
- Sensor, temperature, pressure or monitoring fault caused by fouling or calibration drift, resulting in implausible readings, alarms or protective shutdown
- Mechanical or process fouling caused by cargo residue, corrosion or long service, resulting in reduced transfer, heating, cleaning or vapor-control performance
- Seal, gasket or connection leakage caused by wear, thermal cycling or cargo incompatibility, resulting in cargo or vapor leakage
- Pump, fan, motor or hydraulic drive failure where fitted caused by electrical, lubrication or control faults, resulting in inability to operate or reduced capacity
- Valve, actuator or remote-control failure caused by corrosion, sticking or wiring faults, resulting in incorrect routing or unavailable operation
- Sensor, temperature, pressure or monitoring fault caused by fouling or calibration drift, resulting in implausible readings, alarms or protective shutdown
- Mechanical or process fouling caused by cargo residue, corrosion or long service, resulting in reduced transfer, heating, cleaning or vapor-control performance
- Seal, gasket or connection leakage caused by wear, thermal cycling or cargo incompatibility, resulting in cargo or vapor leakage
- Pump, fan, motor or hydraulic drive failure where fitted caused by electrical, lubrication or control faults, resulting in inability to operate or reduced capacity
- Valve, actuator or remote-control failure caused by corrosion, sticking or wiring faults, resulting in incorrect routing or unavailable operation
- Sensor, temperature, pressure or monitoring fault caused by fouling or calibration drift, resulting in implausible readings, alarms or protective shutdown
- Mechanical or process fouling caused by cargo residue, corrosion or long service, resulting in reduced transfer, heating, cleaning or vapor-control performance
- Seal, gasket or connection leakage caused by wear, thermal cycling or cargo incompatibility, resulting in cargo or vapor leakage
- Pump, fan, motor or hydraulic drive failure where fitted caused by electrical, lubrication or control faults, resulting in inability to operate or reduced capacity
- Valve, actuator or remote-control failure caused by corrosion, sticking or wiring faults, resulting in incorrect routing or unavailable operation
- Sensor, temperature, pressure or monitoring fault caused by fouling or calibration drift, resulting in implausible readings, alarms or protective shutdown
- Mechanical or process fouling caused by cargo residue, corrosion or long service, resulting in reduced transfer, heating, cleaning or vapor-control performance
- Seal, gasket or connection leakage caused by wear, thermal cycling or cargo incompatibility, resulting in cargo or vapor leakage
- Pump, fan, motor or hydraulic drive failure where fitted caused by electrical, lubrication or control faults, resulting in inability to operate or reduced capacity
- Valve, actuator or remote-control failure caused by corrosion, sticking or wiring faults, resulting in incorrect routing or unavailable operation
- Sensor, temperature, pressure or monitoring fault caused by fouling or calibration drift, resulting in implausible readings, alarms or protective shutdown
- Mechanical or process fouling caused by cargo residue, corrosion or long service, resulting in reduced transfer, heating, cleaning or vapor-control performance
- Seal, gasket or connection leakage caused by wear, thermal cycling or cargo incompatibility, resulting in cargo or vapor leakage
- Pump, fan, motor or hydraulic drive failure where fitted caused by electrical, lubrication or control faults, resulting in inability to operate or reduced capacity
- Valve, actuator or remote-control failure caused by corrosion, sticking or wiring faults, resulting in incorrect routing or unavailable operation
- Sensor, temperature, pressure or monitoring fault caused by fouling or calibration drift, resulting in implausible readings, alarms or protective shutdown
- Cavitation from poor suction, low tank level or restricted valves causes vibration, noise and reduced cargo rate
- Mechanical-seal or shaft-seal wear causes cargo leakage into the pump room
- Bearing, shaft or coupling wear causes abnormal vibration, noise or rising temperature
- Impeller erosion, corrosion or fouling reduces discharge pressure and capacity
- Drive, governor, steam, electric or control faults as applicable cause reduced speed, inability to start or protective shutdown
- Cavitation from poor suction, low tank level or restricted valves causes vibration, noise and reduced cargo rate
- Mechanical-seal or shaft-seal wear causes cargo leakage into the pump room
- Bearing, shaft or coupling wear causes abnormal vibration, noise or rising temperature
- Impeller erosion, corrosion or fouling reduces discharge pressure and capacity
- Drive, governor, steam, electric or control faults as applicable cause reduced speed, inability to start or protective shutdown
- Cavitation from poor suction, low tank level or restricted valves causes vibration, noise and reduced cargo rate
- Mechanical-seal or shaft-seal wear causes cargo leakage into the pump room
- Bearing, shaft or coupling wear causes abnormal vibration, noise or rising temperature
- Impeller erosion, corrosion or fouling reduces discharge pressure and capacity
- Drive, governor, steam, electric or control faults as applicable cause reduced speed, inability to start or protective shutdown
- Cavitation from poor suction, low tank level or restricted valves causes vibration, noise and reduced cargo rate
- Mechanical-seal or shaft-seal wear causes cargo leakage into the pump room
- Bearing, shaft or coupling wear causes abnormal vibration, noise or rising temperature
- Impeller erosion, corrosion or fouling reduces discharge pressure and capacity
- Drive, governor, steam, electric or control faults as applicable cause reduced speed, inability to start or protective shutdown
- Cavitation from poor suction, low tank level or restricted valves causes vibration, noise and reduced cargo rate
- Mechanical-seal or shaft-seal wear causes cargo leakage into the pump room
- Bearing, shaft or coupling wear causes abnormal vibration, noise or rising temperature
- Impeller erosion, corrosion or fouling reduces discharge pressure and capacity
- Drive, governor, steam, electric or control faults as applicable cause reduced speed, inability to start or protective shutdown
DESMI
9- Loss of suction or cavitation caused by low inlet head, blocked strainers, closed valves or air ingress can produce noise, vibration and reduced delivery
- Seal or gasket deterioration caused by wear, temperature or chemical attack can produce visible leakage or loss of prime
- Bearing, shaft or coupling wear caused by misalignment, poor lubrication or prolonged vibration can show as rising noise, temperature or vibration
- Impeller, screw, rotor or internal pumping-element wear caused by solids, corrosion or abrasive service can result in reduced capacity and longer transfer times
- Driver or control faults caused by motor, hydraulic, protection or instrumentation problems can cause failure to start, trips or unstable speed
- Loss of suction or cavitation caused by low inlet head, blocked strainers, closed valves or air ingress can produce noise, vibration and reduced delivery
- Seal or gasket deterioration caused by wear, temperature or chemical attack can produce visible leakage or loss of prime
- Bearing, shaft or coupling wear caused by misalignment, poor lubrication or prolonged vibration can show as rising noise, temperature or vibration
- Impeller, screw, rotor or internal pumping-element wear caused by solids, corrosion or abrasive service can result in reduced capacity and longer transfer times
- Driver or control faults caused by motor, hydraulic, protection or instrumentation problems can cause failure to start, trips or unstable speed
- Loss of suction or cavitation caused by low inlet head, blocked strainers, closed valves or air ingress can produce noise, vibration and reduced delivery
- Seal or gasket deterioration caused by wear, temperature or chemical attack can produce visible leakage or loss of prime
- Bearing, shaft or coupling wear caused by misalignment, poor lubrication or prolonged vibration can show as rising noise, temperature or vibration
- Impeller, screw, rotor or internal pumping-element wear caused by solids, corrosion or abrasive service can result in reduced capacity and longer transfer times
- Driver or control faults caused by motor, hydraulic, protection or instrumentation problems can cause failure to start, trips or unstable speed
- Loss of suction or cavitation caused by low inlet head, blocked strainers, closed valves or air ingress can produce noise, vibration and reduced delivery
- Seal or gasket deterioration caused by wear, temperature or chemical attack can produce visible leakage or loss of prime
- Bearing, shaft or coupling wear caused by misalignment, poor lubrication or prolonged vibration can show as rising noise, temperature or vibration
- Impeller, screw, rotor or internal pumping-element wear caused by solids, corrosion or abrasive service can result in reduced capacity and longer transfer times
- Driver or control faults caused by motor, hydraulic, protection or instrumentation problems can cause failure to start, trips or unstable speed
- Loss of suction or cavitation caused by low inlet head, blocked strainers, closed valves or air ingress can produce noise, vibration and reduced delivery
- Seal or gasket deterioration caused by wear, temperature or chemical attack can produce visible leakage or loss of prime
- Bearing, shaft or coupling wear caused by misalignment, poor lubrication or prolonged vibration can show as rising noise, temperature or vibration
- Impeller, screw, rotor or internal pumping-element wear caused by solids, corrosion or abrasive service can result in reduced capacity and longer transfer times
- Driver or control faults caused by motor, hydraulic, protection or instrumentation problems can cause failure to start, trips or unstable speed
- Loss of suction or cavitation caused by low inlet head, blocked strainers, closed valves or air ingress can produce noise, vibration and reduced delivery
- Seal or gasket deterioration caused by wear, temperature or chemical attack can produce visible leakage or loss of prime
- Bearing, shaft or coupling wear caused by misalignment, poor lubrication or prolonged vibration can show as rising noise, temperature or vibration
- Impeller, screw, rotor or internal pumping-element wear caused by solids, corrosion or abrasive service can result in reduced capacity and longer transfer times
- Driver or control faults caused by motor, hydraulic, protection or instrumentation problems can cause failure to start, trips or unstable speed
- Mechanical seal/packing leakage, typically indicated by cargo leakage, odor or pump-room alarm
- Cavitation or suction restriction, typically indicated by noise, vibration and reduced cargo rate
- Impeller/wear-ring erosion or corrosion, typically indicated by reduced head/capacity
- Bearing or drive wear, typically indicated by vibration, overheating or abnormal noise
- Control/ESD or remote valve fault, typically indicated by pump trip, inability to start or unsafe shutdown response
- Mechanical seal/packing leakage, typically indicated by cargo leakage, odor or pump-room alarm
- Cavitation or suction restriction, typically indicated by noise, vibration and reduced cargo rate
- Impeller/wear-ring erosion or corrosion, typically indicated by reduced head/capacity
- Bearing or drive wear, typically indicated by vibration, overheating or abnormal noise
- Control/ESD or remote valve fault, typically indicated by pump trip, inability to start or unsafe shutdown response
- Mechanical seal/packing leakage, typically indicated by cargo leakage, odor or pump-room alarm
- Cavitation or suction restriction, typically indicated by noise, vibration and reduced cargo rate
- Impeller/wear-ring erosion or corrosion, typically indicated by reduced head/capacity
- Bearing or drive wear, typically indicated by vibration, overheating or abnormal noise
- Control/ESD or remote valve fault, typically indicated by pump trip, inability to start or unsafe shutdown response
IMO
1
- Bearing, shaft or guide wear causes vibration, abnormal noise, reduced efficiency or mechanical contact
- Tank-top, shaft or mechanical seal leakage causes visible cargo leakage, vapour release or contamination of adjacent systems
- Hydraulic, electric or mechanical drive faults cause reduced speed, inability to start or protective trips
- Impeller or pump-stage fouling, erosion or damage causes low discharge pressure and reduced cargo rate
- Dry running, poor suction or inadequate tank level causes overheating, vibration or accelerated wear
- High flow rate and pressure capabilities
- Robust mechanical design for harsh marine environments
- Easy maintenance with accessible components
- Potential for mechanical seal failure if not properly maintained
- Bearing temperature rise can indicate potential issues
- Impeller cavitation erosion may require frequent replacement