Multi-Wing 7W Replacement: How to Specify a Complete UTEK-DELE 9W2 Impeller

Confirm the replacement scope before requesting a quote

UTEK-DELE supplies a configured 9W2 complete axial impeller as a direct replacement for the corresponding Multi-Wing 7W assembly. This route replaces the assembled rotating unit, including the hub and blades specified together. Keep the original 7W code, diameter, rotation, pitch and machine reference on the enquiry. Those details identify the version to reproduce at the machine interface and the operating duty to agree before ordering.

Use this guide when you have a 7W assembly and need to decide whether your technical and purchasing records are sufficient to order the 9W2 replacement. The machine may stay in service for years after the first replacement. A usable order therefore has to identify more than the profile. It also needs to explain which parts stay in service, which parts arrive in the shipment, which drawing controls the interfaces, and which verification releases the installed machine back to operation.

UTEK-DELE is an independent supplier. Multi-Wing is referenced to identify the original equipment. UTEK-DELE offers its own products, drawings and documentation for the replacement assembly. This article focuses on one assembly route. The axial fan blade and impeller model cross-reference covers other original references, including blade replacement routes with their own ordering scope.

What arrives with a complete impeller replacement?

The line item should specify the supplied hub and blades as one configured assembly. Ask the supplier to mark which mounting components ship with the assembly and which ones the customer supplies or retains. A quotation that leaves the bush, fasteners, spacer or adapter implicit may be hard to compare and can create an extra order before installation. Separate the mechanical supply boundary from any service that takes place at the customer's site.

Does a 7W blade marking identify the complete unit?

A blade marking is a useful starting point. Read the assembly label or machine bill of materials to recover the original build. Retain the complete string as photographed, including separators and any suffix. If you transcribe it into a purchasing system, attach the original image beside the transcription. An incomplete code can leave several possible configurations, and the omitted portion may describe the drive or hardware that determines fit.

What counts as a confirmed match?

The buyer and the supplier should refer to the same assembly drawing and revision. The drawing must show that the proposed mounting interface and clearance envelope suit the machine, and the engineering review must address the required working point. Ask the responsible owner to identify the documents that govern installation, test and release. Keep fit approval, performance review and commissioning acceptance distinct so a positive answer to one is recorded with its proper scope.

Why request an assembly instead of mixing blade sets?

The 7W to 9W2 route specifies a new hub and blades configured together. A blade transplant would be a different technical and supply decision, with a separate retention interface and balancing responsibility. Use the complete assembly route for this mapping. If the project requires reusing the incumbent hub, pause that request and ask the responsible engineer to establish the permitted repair scope from the machine documentation.

The European modular impeller brochure lists 7W and 9W2 as separate W airfoil profile designations. Use the correct original code when identifying the assembly.

Build an identification packet for the installed 7W

Start with one machine record per physical assembly

Give each unit a machine or location ID before collecting the pictures and dimensions. Use the same ID in the photo filenames, field notes, drawing request and quote. A plant may have several similar fans installed in the same row. Their face views can look alike while the shaft ends, spacers, rotation or prior service changes differ. A label from one bay and measurements from another can produce a plausible but incorrect enquiry.

Take one context photo showing the drive, guard and airflow arrangement, then attach separate views of the nameplate, hub and mounting side as permitted by the equipment owner. Add a date, machine ID, and observer or drawing reference to the record. When site safety or access prevents a photo, specify what was inaccessible and provide the corresponding approved drawing or request further inspection. An explicit unknown helps the supplier allocate the correct review step.

For fleet work, group units only after the owner has checked their machine revisions and existing fan assemblies. Give each group an installation list and a representative inspection record. Mark any unit that has been repaired, retrofitted or fitted with a substitute in the past. As-maintained records are particularly important when a fleet order assumes one common mounting interface.

Preserve the evidence behind every dimension

Set up the record with three columns: requested field, observed value, and evidence. A bore from a controlled drawing is a different kind of information from a tape reading taken through a guard. Keep the drawing revision beside the former and the measuring method and access constraint beside the latter. Where inspection values and drawings disagree, send both records and ask the equipment owner which one describes the installed condition.

Do not rely on a photograph to establish scale if the reference and the feature are in different planes. Mark the units and datum on the sketch. If the shaft extends through several parts, identify which visible surface belongs to the shaft and which belongs to a sleeve, bush or hub. An engineer can then tell whether a measurement describes the machine interface or a removable component.

Capture the original equipment reference even if an owner plans to replace a damaged unit from stock. Stock descriptions often shorten the assembly to a nominal diameter and blade family. Keep the full identification in the purchasing file and add the customer stock code as a separate field. Future spare orders can then be traced without assuming the text on a bin label is a complete fan specification.

If the label is missing, work from the physical arrangement

Use the machine model and serial or asset reference to request the original drawings. Where safe inspection is available through qualified personnel, collect a dimensional sketch and photos from opposite sides of the assembly. Record whether each observation was taken from the drive side, discharge side or another named view. The two views clarify details that a face photo hides, such as an adapter behind the hub or an axial offset between the flange and blade sweep.

Mark each field as observed, drawing-based, or still open. A field that is important to fit, such as the mounting pattern, must stay open until confirmed. Attach the original 7W identification wherever it has actually been established. If the model identification remains uncertain, ask for identification review before asking for an order against the 7W mapping. Preserve the possibility that a previously serviced machine has a different assembly from the one in its original parts list.

An enquiry can progress in stages. A supplier can review the likely assembly route while the customer obtains approved dimensions. The drawing and order should still reflect the actual fit and duty information before release. This staged approach keeps the equipment identification work visible and avoids converting an early budget quote into an unconditional purchase order.

The original manufacturer explains that its complete ordering code combines design information for a customized fan. Preserve the full code or attach a photograph of the label to the enquiry.

Compare the mounting envelope on one drawing

Define a shared axial reference plane

Pick the machine-side mounting face used to locate the existing assembly and name it on the sketch. Ask for the proposed impeller drawing to use that same plane, or for the designer to give the relationship between its datum and the machine datum. Confirm which direction is positive along the shaft. A quoted offset is only comparable when both people measure from the same feature and in the same direction.

The plane may belong to a drive flange, an adapter or a mounting face associated with a bush. Identify that hardware in the picture or the original sectional drawing. If an adapter is reused, keep the adapter face and its thickness in the interface stack. If it is removed or supplied with the new impeller, ask for the resulting position of the assembled blades relative to the shroud and adjoining equipment.

For example, a drawing may show the hub centered on its own flange while the installed assembly sits further along the shaft because of an existing spacer. Both drawings can be correct in their own reference systems. An overlay becomes useful after the drawings share a named reference face. Record the side of the flange that locates the assembly and confirm which spacer appears in the delivered package.

Record the drive connection as an interface, not a bore alone

Describe the form of the connection before listing dimensions. Indicate whether it is a direct shaft fit, a bush arrangement, or a bolted flange. Record the bore, pilot or locating diameter that actually applies. Add the key or other drive feature if present, plus the bolt count, arrangement and relevant thread or hole detail from the controlled drawing. Where the fit relies on a specific adapter or bush code, retain the full code and revision.

Name the owner of each retained interface. The maintenance team can usually establish what remains in the machine. The designer must approve an alternate interface where equipment documentation requires it. Ask the supplier drawing to show both the proposed connection and the related fit information, so the review can distinguish a compatible assembly from an assembly that depends on extra hardware or design approval.

Use the manufacturer's documentation for the coupling and hardware selected for the actual build. Generic tightening, insertion depth or adjustment instructions should not substitute for those documents. If documentation does not identify the approved connection, request it before installation. This is also a useful procurement checkpoint because it brings the required instructions and hardware into the same order scope.

Check the complete swept envelope

Record the approved impeller diameter, how it was identified, and the shroud opening geometry. Ask for the forward and rearward limits of the proposed blade envelope relative to the mounting datum. Inspect the assembly drawing for the pitch position associated with the quoted configuration. A nominal diameter alone does not reveal where the blade passes in relation to a guard, a support, the radiator or a duct transition.

Ask the equipment owner to state the clearance requirements and applicable installation conditions. Include eccentricity or access constraints if the shroud or structure is known to be irregular. An engineer should review the machine-side clearance with the intended mounting position, approved operating conditions and applicable design allowances. Do not read an installation limit off a family catalogue table or assume a clearance seen at rest is the acceptance criterion.

Document clearance evidence in named locations. A radial check at the ring describes a different interaction from an axial check at the guard. For a tight cooling package, request a side view showing the mounting face, blade envelope, radiator and relevant structure. This gives the installer a practical point of comparison at receipt and gives purchasing a drawing reference if the delivered assembly differs from the approved version.

Specify rotation from an agreed viewing side

Write the direction of rotation alongside the viewpoint used to describe it. Add the intended airflow direction separately. Use a simple arrow on a machine sketch or on an annotated photograph taken by the owner. An unqualified clockwise note can be interpreted from opposite sides and appear reversed, even when two people are looking at the same fan. The replacement drawing should adopt the agreed notation.

Capture any relevant motor or drive information with that view. The motor nameplate may provide information that is useful to the review, but the original impeller's duty, actual control setting and arrangement still matter. If the machine uses variable speed or a particular normal operating range, describe the requirement and reference the approved control limits. Keep any unusual operating modes visible for engineering review instead of assuming they carry over from the normal operating point.

Reference: UTEK-DELE adjustable axial blade range and 9W2 catalogue entry. The ranges describe a product family screen. Individual combinations, fit and performance are confirmed on the offered assembly drawing and the application requirements.

UTEK-DELE W-series workshop assembly view for orientation.UTEK-DELE workshop photograph showing a hub and blade mounting area.

Carry over the required duty, then approve the actual configuration

Describe what the fan has to accomplish on this machine

Provide the required airflow and pressure if available, the operating speed or speed range, and the relevant temperature and air-side conditions. Explain where the duty was specified or measured. A requirement from a machine designer, a value inferred from a motor label and a reading from a serviced unit should remain distinct. If measurements were taken before the fault, include the date and the equipment condition so the reviewer can decide whether those values are representative.

Note the inlet and outlet arrangement, any radiator or heat exchanger restriction and the direction in which the fan operates. Compare proposals in the context of the same duty and installation. A catalogue selection, a fan test arrangement and a measurement in the installed equipment each have different conditions. Ask the reviewer to state which conditions apply to the offered build and which remain to be checked at commissioning.

Record changes that could invalidate the old setup

If the owner has changed the radiator, filters, shroud, motor, gear ratio or speed control since the original fan was installed, make those changes explicit. The replacement project may retain the physical interface while changing the target operating point. When this happens, the order should say which original features must be maintained and which performance requirement has changed. That lets the supplier discuss a selected replacement without treating the old configuration as the current requirement by default.

For an emergency spare, obtain the original approved scope first. For a planned retrofit, request a comparison that includes the revised duty and evidence supporting it. In either case, keep the agreed design point, accepted operating range and required test method on record. The responsible engineer can use those records to decide whether a configuration is released as an equivalent replacement at the specified duty or needs a separate design review.

Record pitch as a configuration field with a method

Ask which reference and measuring point the drawing uses to define the pitch. Record both the value and method if the original owner has the setup documentation. If an incumbent blade is damaged or has moved, the observed position may describe the failure rather than the original setting. Keep the observed condition and the approved setting separate. Use the replacement drawing to agree the selected setting and how the received unit should be checked.

An indicated angle recorded on one profile cannot automatically be copied to another profile. The original and proposed arrangements may use different references for the reading. The supplier needs the requested operating duty and the mounting geometry to select the supplied assembly. Where the necessary settings are already specified on an approved project drawing, attach the drawing revision so there is one governing record.

Confirm material from the offered part record

Identify air temperature, exposure, corrosive conditions and any project-specific material or electrical requirements. Ask for the exact material on the offered configuration and the supporting document scope. An incumbent material code can be a useful identification clue, but it does not establish that the same abbreviation describes the same formulation across manufacturers. The part drawing and the project material documentation should identify the version being offered.

If procurement requests a replacement for classified or otherwise regulated equipment, give the approval requirements to the responsible owner and supplier before quoting. A material property or a standalone component document does not by itself establish equipment conformity. Ask which product and assembly documentation apply in the destination market, and keep the approved document set linked to the specific build. Avoid relying on an unrelated product family page as release evidence.

Apply the same order workflow to different installation constraints

Cooling package with very limited axial space

Consider a radiator assembly whose service notes identify a 7W and whose maintenance team plans to leave the motor mount and ring in place. The required inputs for this case are the complete original code, the approved envelope, the mounting face and the relative position of the radiator and guard. The replacement drawing should show the relevant face and the forward and rearward blade limits. The owner needs to verify the clearance requirements in the application instead of relying on a family diameter match.

If the radiator was renewed and its mounting bracket changed, add the revised package drawing to the enquiry. Record whether the new bracket changes the occupied space or the airflow resistance the fan sees. The first result needed is a drawing that demonstrates interface and packaging compatibility. The duty review can then address the changed equipment condition without confusing a fit approval with approval of the cooling result.

Cooling tower maintenance order with several machine variants

If the maintenance order covers several tower cells, record their machine tags and fan identifiers individually. Assign a common configuration only when the installed hub connection, offset, diameter, rotation and operating duty are confirmed to match. Keep the guard and shroud details in the record for each cell that differs. A delivery plan can then specify which configuration goes to which cell and which parts must be held until the site confirms its interface.

Use the short field clip below to orient the photos and machine sketch when discussing a large W-family installation. It is a visual reference for equipment access and general installation context. Match the actual 7W assembly and the proposed 9W2 using project drawings and approved instructions. Obtain the equipment owner's release before any operational check.

Similar family pages for cases outside this mapping

The W-family product pages show what information is normally published at family level. The UTEK-DELE 6W product family offers another example of a W-profile page, while the UTEK-DELE U10W product family is a separate enquiry route for projects with different constraints. The presence of another profile on the site does not place it in the 7W replacement route. Use these pages to compare how product information is presented, and request a separate engineering selection if the installed reference is different.

Turn the engineering review into a comparable purchase order

Write the quotation scope around one assembly revision

Start with the original full code and machine ID, then identify the offered 9W2 assembly and drawing revision. Keep the requested scope in the order text: complete impeller assembly, supplied mounting hardware, items retained by the buyer and any installation service separately. Identify what is delivered balanced or checked by the supplier according to the approved scope, and ask which document accompanies the shipment. The quotation should make clear when fit is reviewed and what is still subject to the equipment owner's release.

Keep alternates in separate quotation lines. A blade-set price, a fully assembled and documented impeller and a site-installed replacement represent different packages. A price comparison becomes useful when each bidder prices the same configuration, deliverables and destination. If the scope differs, ask bidders to price the missing items or show the difference as a separate line so a purchaser can make an informed decision.

Write the proposed assembly identifier on both the technical acceptance record and the purchase order. If a later quotation revision changes its mounting hardware or selected settings, give it a new review entry. A buyer can then see whether the commercial revision changed only lead time or introduced a different part. Treat a change in scope as a technical question before the order is released.

Keep commercial and technical assumptions visible

Ask all bidders to state quantity, quotation date, currency, named delivery terms, destination and inclusions. Compare expected freight, tax treatment, warranty and any planned site support using the same assumptions. Mark items such as drawing review, an approved first article and installation support where they are included or separately priced. If a price is valid for a specific quantity or shipping window, retain the condition with the record.

For a large machine or an installation requiring planned access, the order must also account for outage timing and inspection responsibility. Ask who inspects the delivered assembly, who supplies the retained hardware, and who will confirm the machine clearances before it is returned to service. Cost and lead time are more useful when this work is part of the quotation scope. If different bidders require different review or installation tasks, keep them in separate rows rather than absorbing them into an undefined unit price.

The buyer may ask for a price before all interfaces are known. In that case, ask for the quotation to mark the remaining inputs, the scope of the budget figure and which approvals must precede a binding order. The final commercial comparison can be updated after the drawings and operating point have been reviewed. This is especially useful when one bidder assumes a retained adapter and another includes a new mounting package.

Release the first article and preserve its evidence

Before the proposed unit is dispatched, request the documentation agreed for the configuration and check that the identifier on the drawing matches the order. On arrival, record the product and shipment identifiers and inspect against the owner's approved process. The approved receiving checks may include review of the mounting interface, protection of the blade envelope in transit and the stated documentation. Give any finding an issue number so the record is tied back to the correct unit.

Before commissioning, use the equipment owner's approved installation and safety procedures. Confirm which qualified team is responsible for installation, rotation and clearance checks, and the operational measurements called for by the release plan. The article cannot set acceptable speed, vibration, tightening torque or clearances for a machine it has not assessed. The test plan should reference actual design limits and commissioning requirements and identify what is measured and who signs off.

Retain the final drawing, tested conditions, identified assembly and release notes under the machine ID. When the next spare is purchased, this file can be used to verify whether the same revision and operating point still apply. A configuration-controlled spare record reduces repeated identification effort and makes differences between subsequent fleet units easier to catch.

Five common errors to catch before approving the order

1. Treating a code on the blade as the assembly identity

The original 7W marking helps identify the profile. The complete impeller line still needs the hub, installation and duty information. Open two fields in the purchasing record, one for the observed profile and another for the original complete code. Where the complete code cannot be recovered, send a named set of photos and dimensions rather than constructing an unverified code.

2. Combining a blade-only offer with a complete-assembly comparison

The 9W2 mapping here covers the assembled unit. Clarify whether the order retains the existing machine-side adapter, includes a replacement bush or supplies all hardware listed on the drawing. If another bid supplies only blades, put it in a different scope category. A price difference between those line items does not describe a difference for the same supplied product.

3. Measuring offset from the wrong face

Use the installed mounting face as a shared reference and label it in the drawing package. If the drawing begins at the centre of the hub or at a flange on the opposite side, record the relation between the references. Compare the swept envelope in the machine, including retained hardware, instead of comparing two isolated hub dimensions.

4. Letting pitch or rotation travel without its reference

State the reference view for rotation and the angle definition for pitch. Require these references on the approved drawing or associated configuration sheet. Airflow direction and rotor rotation are separate descriptions. If the operator's notes and drawing seem to conflict, have the responsible engineer resolve the notation before ordering.

5. Recording fit as the final acceptance

Fit approval makes the dimensional decision traceable. The owner must also confirm the approved application and commissioning results for the working assembly. Separate the drawing review, receipt inspection and operational release on the checklist. The buyer will then have a record of what was approved at each step and who can resolve a discrepancy.

Prepare a review packet in seven steps

1. Record machine ID, exact original 7W code, drawing revision and an installation overview.
2. Mark what stays in the machine, what ships in the complete 9W2 assembly and which mounting hardware needs explicit scope.
3. Add the drive-side view, agreed rotation reference, mounting face and measured or drawing-based dimensions.
4. Attach the required duty, speed and operating environment. Describe any changes to the cooling package or controls.
5. Ask for a matching assembly drawing, documentation list, delivery assumptions and open inputs in the quotation.
6. Review fit and operating duty separately, then release the order against a controlled revision.
7. Use approved procedures for installation and acceptance, and retain the complete evidence file for the next spare.

The UTEK-DELE axial fan replacement enquiry accepts the original part information for a configuration review. Send the reference as it appears on the label, together with the machine drawing or the best available measurements. For a multi-unit enquiry, provide the grouped machine list and the photos for any variant. Ask for the quoted replacement and scope to be tied to the correct group before placing the order.

Quality Assurance for the replacement order

Use the machine-approved requirement, the supplier's assembly drawing and the receiving record as the three anchors of the file. Each describes a different part of the process. The requirement tells the supplier what the equipment must accept and achieve. The drawing shows what was selected. The receiving and commissioning records establish whether the delivered unit and the installation match the approved plan. Keep the identifiers together rather than filing each document under a generic product family heading.

Record exclusions and open questions directly in the technical review. If a destination or application needs additional documentation, obtain it for the specific configuration. Ask for the exact scope of any document offered and verify the issuing information independently where required. Supporting documents should be reviewed against the buyer's own specifications and any requirements applicable to the equipment. The approval should record the responsible owner's acceptance of the actual assembly, not a collection of generic product references.

Worked example of a purchasing record

Here is an illustrative record structure for a site that has recovered its original 7W code but has not yet confirmed the mounting offset. In the identity field, enter the machine tag, the photographed original code, the drive-side view and the date. In the supply scope field, enter a complete 9W2 impeller plus any explicitly quoted mounting hardware. Add a separate line for retained hardware, with a reference to the machine drawing. The technical record can then be reviewed even if the procurement system has only one short line-item description.

In the open-issues field, mark mounting offset as awaiting verification against the machine datum. Identify who can recover the original drawing and who can measure the installed arrangement if the drawing cannot be located. Mark the enquiry stage as budgetary and attach the required operating point from the current cooling package specification if it is known. When the supplier drawing arrives, link the new drawing to the open issue, then record whether the two mounting references can be reconciled. A resolved issue should name the document and revision that closed it.

In the commercial comparison, mark both offers as incomplete until each includes the same assembly, hardware and delivery boundary. If an incumbent quote includes an adapter and the replacement quote excludes it, request both prices with that scope made explicit. If one offer includes the first article documentation and the other treats it separately, compare the resulting total for the same deliverables. Keep the final package with the release record. A future buyer can see why the assembly was accepted and which details must still be checked if the machine configuration changes.

Frequently asked questions

Can UTEK-DELE replace a Multi-Wing 7W impeller?

Yes. UTEK-DELE offers a configured 9W2 complete axial impeller as the direct replacement route for the corresponding 7W assembly. Send the original build code, mounting details and duty so the offered assembly can be specified for the machine.

Can I install individual 9W2 blades in my original 7W hub?

This 7W replacement route supplies a complete 9W2 impeller with its own hub and blades. A blade-only repair using the original hub requires a separate engineering review and an approved service scope.

Which pictures should I attach if I cannot read the label?

Provide permitted views of both faces, the mounting side, the drive and the overall installation. Include the machine reference and a dimensioned sketch from an approved source or a qualified inspection. Mark where the dimensions were taken.

Do I need the airflow and pressure before asking for a quotation?

Include the required operating point if it is available, with the source and conditions. If it is unavailable, submit the existing fan and equipment information and ask which missing inputs must be resolved before technical approval.

How should I record rotation direction?

Write the direction with a named viewpoint, such as viewed from the drive side, and provide a marked photo or sketch if available. Record intended airflow direction separately so the reviewer can check the installation.

Can I use the diameter from a related 9W product page to release the order?

Family information can help screen an enquiry. Release the 9W2 order against the exact configured assembly drawing and the requirements approved for the existing machine.

What should two like-for-like quotations include?

Ask for the same drawing and duty scope, supplied hub and blade assembly, hardware, documentation and applicable support. Compare quantity, currency, delivery terms, destination, lead time and warranty on the same basis.

What should I keep after the first installation?

Retain the original reference, replacement assembly identifier and drawing revision, and the approved receipt and operating checks. Save them under the machine ID for future spare enquiries and verify the revision before reusing the record.

Final Thoughts

Use the complete UTEK-DELE 9W2 assembly to specify the replacement for the corresponding original 7W. Start with the machine and its existing build, then approve the installation interface, operating duty and scope of supply on one controlled set of records. The resulting quotation can be compared on a like-for-like basis, and the final file can support a later spare order without repeating the entire identification process.