Steam Condenser
medium
3 models total
The steam condenser turns turbine or auxiliary exhaust back into feedwater by condensing it under vacuum against circulating seawater, and the vacuum itself, not just the cooling, is what lets the turbine produce useful work in the first place.
Read more — Steam Condenser explained ▾
What makes this type
A steam condenser is a large shell-and-tube heat exchanger operating below atmospheric pressure. Exhaust steam enters the shell side and condenses on tube bundles carrying circulating seawater, while an air ejector or vacuum pump continuously removes non-condensable gases to hold the vacuum. The vacuum matters as much as the cooling: dropping the exhaust pressure below atmospheric increases the pressure differential across the turbine, which is what allows more work to be extracted from the same steam. This distinguishes it from other heat exchangers on board, which simply move heat without an operating pressure that affects the performance of the machine feeding them.
Main components
Tube bundle
Hundreds to thousands of thin-wall tubes, commonly titanium or cupronickel for seawater service, arranged to give maximum surface area in the available shell space.
Water boxes
End covers directing circulating seawater into and out of the tubes, fitted with access covers for tube plugging and cleaning.
Hotwell
The collection space at the bottom of the shell where condensed water gathers before being drawn off by the condensate extraction pump.
Air ejector or vacuum pump
Removes air and other non-condensable gases that accumulate on the steam side and would otherwise blanket the tubes and destroy the vacuum.
Circulating water pump
Draws seawater through the tube side, sized against the design temperature rise across the condenser.
Selection / sizing
- Design vacuum and corresponding saturation temperature, which sets how much work the turbine can recover.
- Circulating water flow rate and inlet temperature, since a warmer sea reduces achievable vacuum.
- Tube material selection against local seawater conditions, particularly where biofouling or erosion-corrosion is a known issue.
- Cleanliness factor assumed in the design, which degrades over the operating cycle between cleanings.
Regulations / Class
Class rules require periodic internal inspection of the condenser during survey, including tube plate and water box examination, as part of the boiler and steam plant survey regime rather than a standalone requirement. There is no dedicated SOLAS or MARPOL chapter for condensers specifically, though MARPOL Annex I governs any oily water discharge if a leak from lubricated machinery contaminates the condensate side.
Typical faults
| Fault | Cause | Consequence |
|---|---|---|
| Tube fouling | Marine growth or scale build-up on the seawater side | Reduced heat transfer, falling vacuum, higher fuel consumption for the same output |
| Tube leak | Erosion-corrosion or pitting at tube ends | Seawater contamination of feedwater, risk of boiler scaling or damage |
| Air ejector underperformance | Worn nozzles or steam supply pressure too low | Air accumulation blankets tubes, vacuum collapses gradually |
| Hotwell level control fault | Level sensor or extraction pump malfunction | Flooding of tube bundle or loss of suction to the extraction pump |
What to look for in a supplier
- Tube material recommendation backed by data on the vessel's actual trading waters, not a generic default.
- Guaranteed cleanliness factor and vacuum performance at stated seawater temperature and flow.
- Support for retubing services, since tube replacement rather than full condenser replacement is the usual repair route.
Watch vacuum trend, not just the instantaneous reading. A slow, steady fall over weeks is fouling that cleaning will fix, while a sudden drop points to an air ejector or tube leak that needs immediate attention.
8000h
Service Interval
25 yr
Typical Lifetime
Typical Manufacturers
Alfa Laval
GEA
Sasakura
3 manufacturers · 3 models
Alfa Laval
1
M10 Condenser
500 kW
· Steam / Seawater
· Gasketed Plate Heat Exchanger (GPHE) steam condenser
Technical Specifications
- Design Pressure M-Line
- >10 bar (145 psi)
- Marine Engine Room Modelle
- T6 (DN60, 800 kW) bis T35 (DN350, 35.000 kW)
- Marine FSRU Modelle
- TS45, T45, T50 (DN450-500, 45.000-55.000 kW)
- Temperaturbereich Standard
- 0-180°C (je nach Modell)
- FSRU Temperaturbereich
- -50 bis 150°C
- Plattentypen
- Chevron, Gemini Doppelwand, FlexFlow™
Product Lines
- M-Line (High Pressure Series: M3, M6, M10, M15)
- T-Series (Industrial: T2, T5, T6, T8, T10, T20, T25)
- AQ-Series (HVAC: AQ1, AQ2, AQ3, AQ4, AQ10)
- Marine Line (Engine Room: T6-T35; FSRU: TS45, T45, T50)
- Baseline (Competitive Line)
- Hygienic Line (Premium)
Heat Exchanger Type
Alfa Laval Gasketed Plate Heat Exchangers (GPHE)
Common Failures & Inspection Points
- Area: Gasket-Verschleiß und -VersprödungCheck: Dichtungen visuell auf Risse, Verhärtung, Quellung und Verfärbung inspizieren; Material-Kompatibilität mit Prozessflüssigkeiten überprüfen; ClipGrip™ Befestigung kontrollieren. Alterungserscheinungen und Elastizitätsverlust sind Austausch-Indikatoren.
- Area: Anpress-Maß und Dichtheit (Tightening Dimension A)Check: A-Dimension gemäß Herstellerangaben mit Messschieber überprüfen (metallischer Kontakt erforderlich). Bolzen sauber halten und schmieren. Überdrehen vermeiden. Regelmäßiges Nachziehen nach Betriebsstunden durchführen. Bei zu niedriger A-Dimension Druckverlust und Leckage zu erwarten.
- Area: Fouling und Verkalkung auf PlattenoberflächenCheck: Druckdifferenz über Wärmetauscher überwachen (Anstieg deutet auf Ablagerungen hin). Wärmeleistung vs. Design-Wert prüfen. CIP-Intervalle nach Performance-Audits optimieren. Ablagerungen erzeugen höhere Pumpenleistung (Energieverschwendung bis 8.000 kWh/Jahr möglich).
- Area: Plattenkorrosion und Risse / DurchbrücheCheck: Nach Demontage Plattenoberflächen auf Lokalmessungen (pittings), Risse und Lochfraß inspizieren. Materialkompatibilität mit Prozessflüssigkeit überprüfen. Ermüdungsrisse besonders an Ecken und Übergängen beobachten. Bei Lochbildung ist Platte unwiederbringlich und muss ersetzt werden.
- Area: Drucktest und DichtigkeitsprüfungCheck: Nach Demontage und Reinigung Hydrostatic Test gemäß Datenblatt durchführen. Prüfdruck typischerweise 1,5× Betriebsdruck. Externe und interne Leckage an allen Anschlüssen und Plattenrändern überprüfen. Befund dokumentieren.
- Area: Plattensequenz und Ausrichtung (5-Punkt-Ausrichtung)Check: Nach Öffnung Plattenfolge und Honeycomb-Muster überprüfen (korrigierte Chevron-Patterns müssen alternieren). 5-Punkt-Alignment System für größere Units aktivieren/validieren. Versatz oder Fehlplatzierung führt zu Kurzschluss und reduziertem Wärmevortrag.
Typ-universelle Inspektionspunkte fuer Alfa Laval Gasketed Plate Heat Exchangers (GPHE) (Alfa Laval, 2026-06). Per-Modell-Specs nicht auto-gefuellt.
Service: Plate-type condenser; check condensate for salinity to detect plate leaks.
Spare Parts: Alfa Laval: Dichtungssatz an Bord vorhalten. Platten-Reinigungschemikalien bevorraten. Lead time: 2-6 Wochen.
Strengths
- High design pressure (>10 bar) suitable for modern high‑speed diesel and turbine plants
- Modular plate construction allows quick capacity changes and on‑site repairs
- Compact footprint compared with shell‑and‑tube condensers, saving valuable engine‑room space
- Standardised gasket system (ClipGrip™) simplifies seal replacement and reduces downtime
Weaknesses
- Plate fouling can increase pressure drop; requires regular monitoring and cleaning in high‑salinity steam cycles
- Gasket material must be compatible with condensate chemistry – unsuitable fluids may cause premature wear
- Maximum capacity limited to the M‑Line series range; very large power plants may need multiple units or alternative designs
Typical Vessels:
Container ship (engine room steam turbine)Bulk carrier (auxiliary boiler condensers)FSRU (Floating Storage Regasification Unit) – TS45, T45, T50 modelsCruise liner (combined heat‑and‑power plant)
Decision Guide: Choose if you need a high‑pressure steam condenser with a small installation envelope, modular capacity and easy on‑site maintenance. Avoid if the vessel requires very large condensation duty beyond the M10 rating or operates with fluids that aggressively attack gasket materials.
Use Cases: Typically installed in marine engine rooms to condense exhaust steam from main propulsion turbines or auxiliary boilers, and on FSRU vessels where compact high‑pressure condensers are required for gas‑to‑liquid regasification cycles.
GEA
1
NT100 Condenser
400 kW
· Steam / Seawater
· Plate-type steam condenser
Common Failures & Inspection Points
- Gasket deterioration
- Plate corrosion
- Vacuum pump failure
Service: GEA plate condenser; maintain vacuum pump oil level.
Spare Parts: GEA: Dichtungssatz an Bord vorhalten. Platten-Reinigungschemikalien bevorraten. Lead time: 2-6 Wochen.
Strengths
- High heat‑transfer area per unit volume gives excellent condensation performance.
- Compact footprint suited for vessels with restricted engine‑room space.
- Modular plate design allows quick inspection, cleaning and replacement of individual plates.
- Stainless‑steel or corrosion‑resistant plate material reduces long‑term degradation.
- Integrated with vacuum pump systems; oil level monitoring is straightforward.
Weaknesses
- Gasket wear can lead to leaks if not inspected regularly.
- Plate fouling or corrosion accelerates maintenance needs when feedwater treatment is inadequate.
- Initial purchase price is higher than conventional shell‑and‑tube condensers.
- Requires a dedicated vacuum pump and regular oil level checks.
- Maximum steam capacity may be limited for very high‑power turbine applications.
Typical Vessels:
Cruise shipFerryRo‑Ro vesselCoastal tankerContainer ship (auxiliary plant)
Decision Guide: Choose if: you need a high‑efficiency condenser in a confined engine room, operate medium‑power steam turbines or auxiliary boilers, and can commit to regular gasket and vacuum‑pump maintenance. Avoid if: the vessel requires very large condensation capacity for high‑output turbines, budget constraints preclude higher upfront cost, or you lack robust feedwater treatment to protect plate surfaces.
Use Cases: The NT100 is typically installed in marine propulsion plants where space is at a premium, such as on cruise liners and ferries using low‑ to medium‑power steam turbines, as well as in auxiliary boiler systems for power generation on various commercial vessels.
Sasakura
1
SC-200
600 kW
· Steam / Seawater
· shell-and-tube steam condenser
Common Failures & Inspection Points
- Tube leakage from corrosion
- Air ingress reducing vacuum
- Tube fouling
Service: Shell-and-tube type; replace zinc anodes and clean tubes at drydock.
Spare Parts: Sasakura: Dichtungssatz an Bord vorhalten. Platten-Reinigungschemikalien bevorraten. Lead time: 2-6 Wochen.
Strengths
- Compact footprint suitable for vessels with limited engine‑room space
- High thermal efficiency due to optimized tube layout
- Robust construction with corrosion‑resistant tubing material
- Zinc anodes are easily replaceable during dry‑dock periods
- Proven reliability on a range of merchant ships
Weaknesses
- Tube material can be prone to corrosion if water chemistry is not tightly controlled
- Vacuum performance degrades quickly with air ingress; requires vigilant sealing maintenance
- Periodic tube fouling necessitates scheduled cleaning at dry‑dock
- Initial purchase price higher than basic, non‑brand condensers
- Spare parts inventory may be limited in regions without a Sasakura dealer
Typical Vessels:
TankerBulk CarrierContainer ShipGeneral Cargo VesselCruise Ship
Decision Guide: Choose the SC-200 when you need a space‑efficient, high‑efficiency condenser for medium‑size merchant vessels and can commit to regular maintenance of anodes and tube cleaning. Avoid if vessel design prioritises lowest upfront cost over long‑term efficiency or if water‑treatment capabilities are insufficient to protect the tubes.
Use Cases: The SC-200 is commonly installed in newbuilds and retrofits where engine rooms have limited clearance, such as medium‑size tankers and bulk carriers. It serves well on ships that run continuously at high load and require reliable condensate recovery for feedwater economy.