Vessel CoreTechnical procurement desk Send RFQ

Blog · Sourcing guide · 2026-07-24

Marine boiler spare parts — a sourcing guide for Aalborg, Miura, Kangrim, Alfa Laval, Mitsubishi and Osaka

Commercial vessels use auxiliary oil-fired boilers as well as exhaust-gas boilers and economisers. For their spare parts, safety-valve set pressure, gauge-glass rating, burner-atomiser identity and refractory specification can affect operation and applicable class requirements. This guide covers frequently encountered OEM families, the data needed to identify each component and the choice between an OEM route and a documented alternative. It does not quote lead times or prices — those depend on the specific unit, vessel schedule and confirmed supply route.

Which OEM families are common on commercial vessels

Several OEM families recur across marine boiler installations. Correctly identifying the family and exact unit is the first step for any RFQ.

  • Alfa Laval (formerly Aalborg Industries) — Mission OL, OS, OC, XW and OM series auxiliary and composite boilers, plus Aalborg AV-6N and XW-EG exhaust-gas economisers. These families are installed across tanker, bulk-carrier and container-vessel fleets.
  • Miura — VWH, VWS and EX series once-through auxiliary boilers, common on tankers and short-sea vessels.
  • Kangrim Heavy Industries — MA, MB and MG series auxiliary and composite boilers on Korean-built vessels.
  • Mitsubishi Heavy Industries (MHI) — MAC and MB series marine boilers on Japanese-built vessels.
  • Osaka Boiler Manufacturing — OB and cylindrical boilers on smaller commercial vessels and coasters.
  • Saacke — burner systems used across many OEM boiler platforms (SKV series burners, SSB oil pressure atomisers).

What we need to identify the correct boiler unit

Boilers are one of the equipment categories where component identity depends on both the boiler OEM and the burner OEM — those are often different companies. Send the following with the RFQ:

  1. Boiler nameplate photo — with maker, model designation (e.g. Alfa Laval Mission OL-15, Miura VWH-2000, Kangrim MA-25), serial number, design pressure and steam capacity.
  2. Burner nameplate photo — separate plate, often on a different housing. Saacke, Weishaupt, Oilon, Volcano or the boiler OEM's own burner (Alfa Laval KBSD, KBO).
  3. Component identity — burner gun, atomiser, nozzle, ignition electrode, photocell / flame sensor, safety valve, gauge glass, blowdown valve, level probe.
  4. Service parameters — design pressure (bar), design temperature (°C), steam capacity (kg/h or t/h), fuel type (MGO, HFO, LSMGO, dual-fuel), and current operating pressure if different from design.
  5. Class society and last survey — DNV, LR, ABS, BV, ClassNK, RINA. For safety valves and gauge glasses this determines the certificate requirement.

Burner components — atomiser and nozzle identity is the RFQ challenge

Burner atomisers, nozzles and burner guns recur in boiler RFQs. A mismatched atomiser flow rate can alter burner performance, an incorrect nozzle angle can damage refractory, and an unsuitable burner-gun length can affect flame stability. Send the following:

  • Atomiser flow rate — stamped on the atomiser body (e.g. "60 GPH 45°B", "200 kg/h 60°S"). The flow rate and the spray angle (measured in degrees) both matter.
  • Atomiser type — pressure jet, steam-assisted, mechanical, spinning cup (rotary cup burners on some Saacke and Volcano platforms).
  • Nozzle size and thread — Danfoss Oil Nozzles are stamped with GPH and spray angle. Aftermarket alternatives (Delavan, Fluidics, Steinen) exist but the flow tolerance differs.
  • Ignition electrode gap and length — specific to the burner OEM.
  • Photocell / flame sensor model — Honeywell, Siemens, Danfoss, Kromschröder, or the burner OEM's own.

Safety valves and gauge glasses — documentation is the identity anchor

Certification requirements for safety valves and gauge glasses must be checked against the vessel documentation and the applicable class rules. At RFQ time, the existing certificate is an important identity reference. Send the following:

  • Set pressure — stamped on the valve body (e.g. "7.5 bar", "15 bar"). This is not the design pressure of the boiler.
  • Nominal size and flange rating — DN25 / DN40 / DN50 / DN65, PN16 / PN25 / PN40.
  • Valve maker — Bopp & Reuther, Sempell, LESER, Crosby (Emerson), Kunkle, Yoshitake, or the boiler OEM's own component.
  • Required documentation — for a complete valve, spring or nozzle, confirm the acceptable certificate and supply route against the technical file and class requirements.
  • Gauge glass — reflex or transparent, working pressure, size (length × width × thickness), and the mica-shield specification for high-pressure service.

Feed water pumps and control

Boiler feed-water pumps are typically small vertical multistage centrifugal units (Grundfos CR, Wilo Multivert, KSB Movitec) or horizontal single-stage pumps. Identification follows the general pump identity pattern. Boiler-specific context includes water treatment and low-flow protection: where a minimum-flow bypass or Yarway / Sarco valve is fitted, confirm the orifice or valve specification against the installation documentation and applicable class requirements.

Refractory bricks and insulation

Refractory linings in oil-fired auxiliary boilers are inspected and renewed according to condition, the maintenance plan and survey requirements. Send the following for a refractory RFQ:

  • Boiler OEM and model.
  • Refractory zone — burner throat, quarl, side wall, roof, floor. Each zone has a different material specification.
  • Material grade — high-alumina castable, ceramic fibre board, insulating firebrick (IFB) with the specific alumina content and service temperature.
  • Quantities per zone — often given by the OEM in a spare-part list or drawing.

OEM route vs verified alternative

For burner nozzles, atomisers, gauge glasses and refractory components, a documented alternative may be considered when material, dimensions, warranty conditions and class requirements allow it. For safety valves, burner guns and OEM-specific assemblies, the acceptable route must be confirmed from the installation documentation because certification, alignment, ignition geometry and sensor wiring can be unit-specific. Vessel Core records the proposed route for each RFQ line.

What we cannot promise before the RFQ is reviewed

Vessel Core does not quote boiler spare-part prices, lead times or supply route before the specific unit, application, class context and identification data are confirmed. Every quotation is prepared for the specific request. A quotation for a safety valve or gauge glass remains preliminary until the applicable documentation requirement is known.

How to send the RFQ

Use the RFQ form. Attach clear photos of both the boiler and burner nameplates, including their complete model and serial information. Use the RFQ evidence checklist to review the fields item by item.

Related reading