Spare Parts for
Azcue Pumps
Centrifugal · self-priming · screw and side channel ranges on seawater, ballast, bilge, fire and fuel duties
Maker names on this page identify equipment and support an RFQ; they do not imply that Vessel Core is an authorised dealer, representative or partner of Bombas Azcue.
Azcue pump ranges found on European tonnage
Bombas Azcue is a Basque family company in Arrona (Gipuzkoa, Spain) that has made pumps since 1910 and runs its own foundry. Its programme for marine and offshore service runs from centrifugal, self-priming and in-line pumps to three-screw, side channel, eccentric screw and piston pumps. The same casing size appears in several impeller, material and seal builds, so the range name alone is rarely enough — the size code and the works number decide which wear parts fit.
CA series
Horizontal self-priming centrifugal. After the first fill the casing keeps enough liquid to prime again on the next start: air drawn from the suction line is mixed with liquid by the impeller, separated in the upper part of the diffuser and expelled through the discharge, so no foot valve is needed. Azcue lists it for ballast, bilge, fire-fighting, engine cooling and general service, and builds it monobloc, bare-shaft or on a baseplate with flexible coupling, with clutch and pulley, or diesel- or petrol-driven. Casing and impeller are bronze or GG25 cast iron with an AISI 316 shaft as standard, and the back pull-out design lets the rotating parts come out without disturbing the pipework. On some sizes the hand of rotation is changed by fitting a different diffuser and impeller, so state the direction of rotation. Wear parts: impeller and diffuser — Azcue renews the pump by replacing these two — mechanical seal, grease-lubricated ball bearing and casing gasket.
CP series
Small close-coupled pump for general service, made self-priming by a venturi air ejector built into the pump or mounted separately; 2CP is the twin-impeller version. Cast iron body and support, brass or bronze impeller and stainless steel shaft as standard, with an all-bronze build for seawater and a pedestal version for a foot-mounted motor with coupling or belt drive. Requests typically cover the impeller, the ejector, the mechanical seal, the pump shaft and bearings.
MN series
Horizontal close-coupled (monobloc) single-stage centrifugal built to the DIN 24255 footprint — the workhorse range on cooling, ballast and general service, dropping into existing DIN 24255 pipework. Impeller, casing and cover wear rings, mechanical seal and shaft sleeve dominate the wear list.
CM, LN and VM/VR series
Vertical in-line pumps used where deck and flat space is tight — cooling circuits, transfer and pressure sets. LN is close-coupled and based on DIN 24255; CM drives through a flexible coupling with spacer; VM uses a rigid coupling with a removable intermediate shaft; VR a rigid coupling with its own ball bearing between pump and motor. On CM, VM and VR the impeller is mounted inverted with the suction facing upwards and the pump turns anticlockwise, so state rotation and orientation when an impeller is ordered. Shaft, sleeve, seal seat and bearing bracket components dominate the wear list.
AN and BOB series
Baseplate-mounted single-stage units driven through a flexible coupling. AN is Azcue's bearing-bracket pump based on DIN 24255, with back pull-out design, a closed radial impeller and a DIN 24960 mechanical seal as standard; BOB is the robust bearing-bracket range Azcue lists for fire-fighting, cooling and marine service, and it can be made self-priming with a vacuum pump. Requests cover the impeller, the wear-ring pair, the seal assembly, drive-end and non-drive-end bearings and the coupling element. DIN 24960 has been replaced by EN 12756, and the mechanical seal size finder gives the seal dimensions from the shaft diameter.
BT series — three-screw pumps
Three-screw pumps for lube oil and for gas oil, diesel and fuel transfer and feed, built in executions shown by the letters after BT: MB close-coupled for transfer; HM, IL, LH and LV self-priming units; HH for high pressure; DF/DG for the largest frames; LSH/LSV for low-sulphur fuel oil; and MGH/MGV with a magnetic coupling instead of a mechanical seal. BLOC is a compact module with pumps, filters and valves. Component requests centre on the screw set (driving and idler spindles), the insert or liner, shaft seal, bearings and the relief valve — internal, external or omitted, depending on the code.
MA, MO/BR, RA, KL/KB and RKZ
MA is a close-coupled self-priming side channel pump; MO and BR are multistage versions with the stage count carried in the model code, and BR-RR is the reinforced multistage build Azcue offers for boiler feed and condensate extraction. RA is a bare-shaft or clutch-and-pulley side channel pump for engine seawater cooling, bilge and deck wash. Side channel pumps separate air from the liquid, which suits hydrophore sets, hot water and volatile-liquid transfer. KL and KB eccentric screw pumps and RKZ vertical piston pumps are listed for bilge service, RKZ also for fire duty. State the stage count and the medium so stage components, rotor and stator can be scoped.
Fire, bilge and sanitary sets
Pumps serving fire main, bilge and sanitary systems usually carry documentation expectations beyond the mechanical fit. Flag those duties in the request so the route and paperwork question is settled before quotation.
Azcue wet-end and drive-end components, grouped the way the pump comes apart
Azcue pump requests divide cleanly into the wetted hydraulic components — everything the pumped medium touches — and the drive end that carries the shaft. Grouping a request the same way keeps clearances matched and stops half-overhauls where a new impeller runs against worn rings.
- Impellers and diffusers for CA self-priming casings in bronze or GG25 cast iron, and brass or bronze impellers for CP pumps
- Casing and cover wear-ring pairs, bore held to the size code rather than the range letters
- Mechanical seals, seal seats & elastomer sets rated for the duty — seawater, hot fresh water or fuel
- Gland packing and lantern rings where a packed stuffing box has been fitted in place of the standard mechanical seal — confirm from the pump before requesting
- Pump shafts & renewable sleeves for MN monobloc and CM/LN vertical in-line arrangements
- Drive-end & non-drive-end bearing pairs with retainers for AN and BOB baseplate units
- Casing gaskets, cover gaskets & O-ring kits for CA self-priming casings
- Impeller nuts, keys & lock washers across the centrifugal ranges
- Power rotor and idler screws, inserts or liners & bushings on the BT screw range
- Relief valve springs and seats, suction and discharge covers on BT units
- Flexible coupling elements, spiders & coupling halves on long-coupled AN and BOB sets
- Bearing brackets, lantern pieces & support feet across the monobloc ranges
Centrifugal pump — general arrangement
A licensed photograph of Azcue equipment was not available at publication, so this technical reference illustrates the general arrangement shared by this equipment class.
Illustrative technical reference, not a photograph of Azcue equipment or a Vessel Core installed reference — a licensed photo of this maker's equipment was not available. Vessel Core has no dealership, distribution or partnership agreement with Azcue; it operates as an independent spare parts supplier.
Reading an Azcue nameplate before the request leaves the ship
Azcue nameplates carry the information that lets a request be reviewed without a follow-up round, but the code is built differently from range to range. On MN, LN and BOB it is the series letters, any priming code, the discharge flange size and the nominal impeller diameter — MN 50-250 is a DN50 discharge with a 250 mm impeller — and that pair, not the range letters, sets wear-ring bore and impeller fit. CM, VM and VR give the impeller diameter in centimetres and add an impeller-type letter and a design-modification letter. CA codes give flange size and rated motor power instead of an impeller diameter, followed by a modification letter. Priming codes name the system fitted: EP a separate electric priming pump, EF the same with a float-type purger, VP a compressed-air venturi ejector. Side channel MO and BR codes add a stage code after the pump size and RR where the pump runs on two ball bearings instead of one, while BT screw codes carry the execution, central screw size, pressure range, screw lead, temperature version and relief-valve arrangement. Where the ball bearing of such a pump is relubricated, the bearing grease quantity calculator gives the grams to add from its outside diameter and width, and with the bore and the shaft speed the speed factor n x dm. The works number ties the unit to its build, which matters where a pump has been rebuilt to a different material specification during its service life.
- Series letters plus the complete size code — discharge bore and nominal impeller diameter, the pair that actually decides ring bore
- Any priming code carried in the designation — EP, EF or VP
- Works number, which ties the unit to its original build and reveals any mid-life material change
- Duty point: rated m³/h against rated metres head, plus the actual operating point if it differs
- Speed and direction of rotation viewed from the drive end
- Material combination stated separately for casing, impeller and shaft — mixed rebuilds are common on seawater duty
- Whether the build is self-priming (CA, or CP with its venturi ejector), monobloc (MN), vertical in-line (CM, LN, VM, VR) or baseplate with a flexible coupling (AN, BOB)
- Motor frame and mounting, since a close-coupled replacement is motor-dependent
- Machinery tag from the vessel spare parts list
- Photographs of the nameplate and the removed component
- Measured impeller outside diameter and shaft diameter at the sleeve seat
How Azcue centrifugal, self-priming and screw units actually wear out
Most Azcue requests arrive after a specific symptom, and the symptom usually points at a small group of components. Because the same Azcue casing size ships in several impeller, seal and material builds, the symptom often identifies the build faster than the paperwork does — a pump that has lost head but not current is telling you the ring pair has opened up, whatever the part book says is fitted.
Head falling away at constant speed
Opening wear-ring clearance lets flow recirculate from discharge back to the impeller eye. Discharge pressure sags at unchanged speed while absorbed power holds up or creeps higher — efficiency, not power, is what collapses, so rising kWh per cubic metre delivered is the better indicator. Falling motor current usually points at a restricted suction instead. Ring pair and impeller are normally renewed together, since a new impeller inside worn rings restores very little.
Cavitation damage at the vane inlet
A fouled sea chest strainer or a throttled suction drops the NPSH available below the pump's NPSH required at that flow. The pitting shows on the vane leading edges and shroud rather than the outer diameter, and the pump runs noisy under load. Renewing the impeller without clearing the suction restriction simply repeats the failure.
Seal weeping and sleeve grooving
Mechanical seal faces wear, elastomers harden on hot fresh-water and fuel duties, and the drain begins to drip. By the time the seal is changed the shaft sleeve often carries a groove at the seal track. Treating seal and sleeve as a pair in the request is the usual way to keep the job from being reopened shortly afterwards.
Bearing noise after coupling hardening
On the long-coupled AN and BOB sets, a flexible coupling element that has hardened — or alignment that has shifted on a settled baseplate — throws the load onto the drive-end bearing, which starts to run warm and noisy. Coupling element, both bearings and the shaft should be assessed together rather than the bearing alone. Monobloc CP and MN units have no coupling to blame, so the same symptom there points at the motor bearing or the impeller balance.
BT screw pump losing delivery on transfer duty
On the triple-screw range, wear between the driving spindle, the idler spindles and the insert opens the sealing line along the screw set, and delivery falls off at unchanged speed. Azcue builds BT pumps with an internal relief valve, an external one (E in the type code) or none (S), so check which is fitted before blaming the valve or ordering its parts. Screw set, insert or liner, bushings and, where fitted, the valve spring and seat form the natural request group; state the pumped medium with its temperature and viscosity, because Azcue's standard, MT and HT versions differ in casing material and seal faces.
Self-priming unit that will not pull prime
Impeller-to-casing and wear-ring clearance, the liquid volume retained in the casing, casing joint tightness, diffuser condition and air ingress at the shaft seal all govern whether the unit still recovers prime — plus the suction line itself, which is where air is most often drawn in. Foot and non-return valves sit in the piping rather than in the pump, so they belong in a separate line of the request. Say how long the unit takes to prime, if at all — it narrows the component list considerably.
Galvanic and erosion loss on seawater duty
On seawater duty the cast iron casing, wear ring and joint faces are anodic to a bronze impeller and waste preferentially — graphitisation of the casing and ring bore is the usual finding, while the bronze impeller is cathodically protected and loses metal instead by erosion-corrosion at the vane tips. A rebuild that mixes alloys changes which part is sacrificial, so state the existing casing, impeller and ring material combination rather than letting a replacement be specified in a different alloy.
Packed gland running hot on older CA and CP builds
On units still fitted with gland packing rather than a mechanical seal, the lantern ring has to stay lined up with the flush connection or the packing loses its water. Silted flush lines on seawater duty are the usual cause: the packing carbonises, the gland is tightened to stop the drip, and the sleeve is scored inside a watch. State whether the build is packed or seal-fitted — the two share a shaft but almost nothing else in the wear group.
Azcue pump parts — questions buyers ask
What nameplate data does an Azcue pump RFQ need?
Send the series letters with any priming code and the complete size code — the discharge flange bore and the nominal impeller diameter, as in MN 50-250 — together with the works number, rated capacity in cubic metres per hour, rated head in metres, rotational speed, and the material combination for casing, impeller and shaft. Motor data and the machinery tag from the vessel spare parts list help match the correct build when several similar pumps sit in the same compartment.
Which Azcue pump wear parts are usually requested together?
A centrifugal overhaul normally groups the impeller, the casing and cover wear rings, the mechanical seal with its elastomers, the shaft sleeve, both bearings and the casing gasket. Screw pump work groups the screw set — power rotor and idler screws — the insert or liner, bushings, shaft seal and bearings. Requesting the set together lets clearances be restored as a matched assembly rather than one component at a time.
Can Vessel Core work from a worn part and a photograph instead of a part number?
Yes. Where the part book is not on board, the pump nameplate, a photograph of the removed component, measured impeller outside diameter, seal face diameter and shaft diameter at the sleeve seat are enough to begin identification review. What comes back is a proposed match with the measurements it was derived from shown alongside it — impeller outside diameter, ring bore, sleeve seat — so the ship's engineer can check the figures against the pump in front of them before anything is ordered.
Do you review OEM-route and alternative components for Azcue pumps?
Both routes can be reviewed against the evidence supplied, and on Azcue pumps they split along a component line. Seal faces, bearing pairs and coupling elements are normally standard-dimensioned items — Azcue's AN data sheet, for example, gives a mechanical seal to DIN 24960 as standard — so an equivalence review on those is usually straightforward. Impellers and wear rings are the opposite case — bore and outside diameter have to be held against the size code, and a ring pair machined to the wrong nominal simply reopens the clearance the overhaul was meant to close. Those stay on the OEM route unless the buyer's own reviewer accepts a measured drawing. OEM-route review also suits class-surveyed fire and bilge duties or documentation-sensitive work.
Our Azcue pump has lost head at the same speed. Is it the impeller or the wear rings?
Usually the ring pair first. As the wear-ring clearance opens, flow recirculates from the discharge back to the impeller eye, so discharge pressure sags at unchanged speed while absorbed power holds up or creeps higher. Falling motor current points at a restricted suction instead. The ring pair and the impeller are normally renewed together, since a new impeller inside worn rings restores very little, and the ring bore follows the size code rather than the range letters.
Is Vessel Core connected to Azcue Pumps?
No, and there is no agreement of any kind. Vessel Core holds no dealership, distribution, representation or partnership agreement with Azcue Pumps, and quoting a component against one of its designations implies no approval by the maker and no claim of interchangeability.
Why Bombas Azcue is named on this page
Azcue pumps are identified on this page by series letters, size code and works number because that is the only reliable way to reach the correct wear-ring bore and impeller fit. Maker names help identify equipment and prepare an RFQ. They do not imply that Vessel Core is an authorised dealer, representative or partner of Bombas Azcue or of any other manufacturer named on this page. Models and component descriptions listed here are identification context and do not by themselves establish compatibility, availability or approval for a particular installation.
Send the nameplate and the symptom.
Include the Azcue series and the full size code as cast on the nameplate, the works number, the duty point in m³/h against metres head, the casing, impeller and shaft material combination, and the system the pump serves — seawater cooling, ballast, bilge, fire main, sanitary or fuel transfer. Where the part book left the ship with a previous crew, a nameplate photograph together with the measured impeller outside diameter and the shaft diameter at the sleeve seat is enough to open the file. What comes back is the wear-part group scoped as a matched set — rings and impeller together, seal and sleeve together — rather than a line-by-line pick list that leaves half the clearances worn.
