Marine exhaust gas cleaning spare parts — a sourcing guide for scrubbers and SCR under IMO 2020, EU ETS and Tier III NOx rules

EGCS (scrubber) OEM families — open-loop, closed-loop, hybrid

EGCS product lines may use open-loop, closed-loop or hybrid arrangements, but not every maker or model supports every mode. Confirm the installed system and its approved configuration from the nameplate and technical documentation (Alfa Laval technical overview).

• Wärtsilä Exhaust Treatment (formerly Hamworthy Krystallon) — Open Loop (OL), Closed Loop (CL) and Hybrid (HS) systems delivered as the conventional quench/venturi EGCU Scrubber or the compact Inline Scrubber, plus the newer, lighter-weight IQ Series for container vessels, scalable from roughly 20–70 MW. Wärtsilä also markets V-SOx (venturi-inlet) and Q-SOX designs within the same family (Wärtsilä Exhaust Treatment equipment page; International Filtration News on the IQ Series).
• Alfa Laval PureSOx — three compliance profiles: PureSOx Global (0.5% S, smallest footprint), PureSOx ECA (the original design, for 0.1% S ECA compliance), and PureSOx Flex (switchable), each configurable as open-loop, closed-loop or hybrid, in U-design (side inlet) or inline I-design (Alfa Laval PureSOx product brochure).
• Yara Marine Technologies — open-loop, closed-loop and hybrid arrangements documented across its project history (Yara project release).
• CR Ocean Engineering (CROE) — Open Loop, Closed Loop, and Hybrid designs, further differentiated into In-line (bottom inlet), Off-line (side inlet), and U-line configurations, plus a High Energy Venturi inlet option for fine-particle capture and a Caustic Assist™ Open Loop variant (CR Ocean Engineering; US MARAD Scrubber Selection Guide). CROE has an equipment partnership with Oberlin Filter for closed-loop/hybrid washwater filtration (Maritime Executive on the CROE–Oberlin partnership).
• Fuji Electric (SaveBlue) — cyclone-type SOx scrubber marketed by engine-capacity class: S (~8 MW), M (~12 MW), L (~16 MW), 2L (20–24 MW) and XL, available in open-loop and hybrid types (Fuji Electric EGCS solution page).
• Panasia (PaSOx) — wet scrubber line spanning U-Type (1–80 MW), I-Type (1–80 MW), Square Type (1–70 MW), and Micro Type (1–6 MW) product classes (Panasia scrubber product page).
• DuPont Marine Scrubbers (BELCO) — commercially associated with the BELCO brand (a design lineage established in 1968, later acquired by DuPont), supplied in hybrid, open-loop and closed-loop configurations, mechanically rated for full exhaust temperature (Maritime Executive on a DuPont/Vulica retrofit order). Note: primary and trade sources document this brand as "BELCO" — buyers should confirm terminology in RFQs referencing DuPont™ BELCO Marine Scrubbing Systems.

SCR OEM families for NOx compliance

Selective Catalytic Reduction (SCR) systems inject a urea solution into the exhaust stream upstream of a vanadium-titanium catalyst to reduce NOx to N2 and H2O, and are the primary secondary abatement method for IMO Tier III compliance (ICCT Tier III technology review).

• Wärtsilä NOx Reducer (NOR) — fully integrated with Wärtsilä's four-stroke medium-speed engine range for newbuild and retrofit (Wärtsilä NOR product page). For low-speed two-stroke engines, Wärtsilä/WinGD have deployed pre-turbocharger High-Pressure SCR (HP SCR), including on RT-flex58T-D and X72 engine types (WinGD/Wärtsilä two-stroke HP SCR news).
• Everllence / legacy MAN Energy Solutions — MAN SCR and MAN SCR-HP families for four-stroke and two-stroke applications (technology brochure), including the Cluster 5 Double Layer SCR project supplied to MITSUI E&S (project release).
• Hitachi Zosen (Kanadevia) — Hitz Green SCR — high-pressure Hitz Green SCR systems used in marine diesel applications (Kanadevia marine diesel SCR page).
• Panasia — PaNOx / PaNOx Marine — a dedicated PaNOx Marine variant engineered specifically to meet IMO Tier III standards (Panasia PaNOx product page).
• Kwang Sung (Kwangsung Co., Ltd.) — modular Class 1 through Class 11 SCR product listings for a range of engine outputs (Komachine SCR system listing); confirm the exact maker documentation for the installed unit.

Scrubber wear parts — pumps, nozzles, effluent sensors

Recurring scrubber RFQ categories include mechanical and instrumentation components inside the tower and circulation loop:

• Sea-water pumps (open-loop) — high-flow centrifugal pumps whose duty point, material, seal and motor rating must match the approved system design. Do not use an emissions-guideline normalization basis as a substitute for the installed pump duty (DESMI Scrubber Pumps brochure).
• Circulation pumps (closed-loop) with caustic dosing — lower-flow recirculation pumps paired with a NaOH (caustic soda, typically 40–60% solution) dosing skid, buffer tank with fresh-water make-up, and a water treatment plant with sludge collection (Alfa Laval "Understanding exhaust gas treatment systems").
• Spray nozzles and packing media — wetted internals inside the scrubber tower; classical designs include bubble plate, cyclonic, packed bed, and spray tower configurations (EGCSA Handbook 2012).
• pH, PAH and turbidity sensors — match the sensor, measurement range, method, calibration and data interface to the vessel's approved monitoring arrangement and applicable MEPC.340(77) requirements. Measurement provisions can depend on flow and approval conditions, so do not select a sensor from a generic threshold alone (technical overview of MEPC.340(77) monitoring).
• Wash-water treatment (hydrocyclones, filtration) — closed-loop bleed-off streams are processed through hydrocyclone separators and/or automatic filtration before discharge or sludge storage (Maritime Executive on the CROE–Oberlin partnership).

SCR wear parts — catalyst, dosing, sensors

SCR reactors have their own recurring wear-part categories, distinct from scrubbers:

• SCR catalyst blocks — catalyst chemistry, cell form and operating window vary by engine, fuel, reactor design and approval basis. Match replacement elements to the approved engine and catalyst specification rather than applying a generic chemistry or temperature range (review of vanadium SCR catalysts).
• Urea/AdBlue dosing pumps and nozzles — a reagent pumping unit, dosing unit, mixing unit, and injection nozzle set upstream of the catalyst reactor (Wärtsilä NOx Reducer system overview).
• Urea tank heating — urea/AdBlue solutions can crystallize or freeze at low ambient temperatures, so tank and line heating/insulation is standard for vessels trading in cold-water regions.
• NOx sensors — used for closed-loop dosing control and compliance verification, adapted for marine environmental and vibration ratings.
• Reactor housing internals — catalyst support frame, soot-blowing/cleaning unit (Wärtsilä NOx Reducer system overview).

Class-society and regulatory context

EGCS guidance has evolved through MEPC.184(59), MEPC.259(68) (IMO resolution text) and MEPC.340(77) (technical overview). Which provisions apply depends on the installation's approval basis and dates. Identify the guideline and approved ETM, OMM and compliance documents before requesting monitoring-system components.

The Administration approves the EGCS arrangement, directly or through an authorized recognized organization, against the applicable framework. Confirm the exact approval records—such as the SECC, SECP, ETM and OMM where applicable—rather than relying on a generic statement of compliance. A dated P&I jurisdiction summary can provide background but is not the approval authority.

Discharge restrictions are mutable and may differ by port limits, coastal-state waters, canal rules, discharge mode and voyage conditions. Use the dated P&I summary and the ICCT policy review only as background; before voyage planning, verify the current port, coastal-state and flag-state requirements and the vessel's approved procedures.

OEM route vs verified alternative

For nozzles and packing media, verify dimensions, materials, hydraulic duty and maker acceptance before considering a non-OEM option (CECO Environmental product reference). For pH, PAH, turbidity, CEMS and NOx instrumentation, the sensor, calibration, data logging and reporting interface must match the approved ETM or OMM and obtain any required maker, Administration or class acceptance (monitoring overview). Pump duty, material and seal must match the approved system design (DESMI Scrubber Pumps brochure). SCR catalyst elements must match the engine, fuel, reactor and NOx Technical File requirements; assess any substitution through the applicable approval process (technology brochure).

What we cannot promise before the RFQ is reviewed

Vessel Core sources exhaust-gas-cleaning and SCR spare parts; it does not issue class certification, regulatory approval or a compliance guarantee. Prices, lead times and supply route are not stated before the unit, approved arrangement, fuel in use and documentation context are confirmed. A quotation for sensors or catalyst elements remains preliminary until the applicable approval and technical-file references are available.

How to send the RFQ

Use the RFQ form. Attach the scrubber-tower or SCR-reactor nameplate photo, the OEM system model and serial number, the discharge system type (open-loop, closed-loop, or hybrid), and the current fuel type in use. Or use the RFQ evidence checklist to walk through the fields item by item.

Related reading

• Marine cooling water sourcing guide
• Marine fuel injection sourcing guide
• Marine pumps sourcing guide
• RFQ evidence guide
• RFQ case notes