Establish exactly what the quoted unit includes
Module, element, cassette and frame identify different supply levels. One MBR quotation may supply membrane components alone, while another includes a block with manifolds and aeration. Neptuno's MBR catalogue distinguishes modules and cassettes with their membrane areas. Add a component list and quantities to the order so that proposals can be compared on the same basis.
Identify membrane area per unit and the total area included in the quotation. Distinguish declared active area from any other area definition in the catalogue. Check the full model, revision and materials: an abbreviated reference can conceal connection or area variants. The unit price should match the precise reference that will subsequently appear on the purchase order and delivery documentation.
Turn exclusions into visible line items
Prepare a common comparison sheet before requesting price revisions. Mark each item included, excluded or unresolved, with its quantity and responsible party. Seals, clamps, adapters, manifolds, diffusers and fixings may determine whether replacement can be completed within the planned outage. An item with no stated price should not be treated as having zero cost or being available elsewhere automatically.
Separate site activities: removal, cleaning or disposal of old equipment, lifting, installation, programming and testing. Establish whether support is remote or on site, the included duration and who provides instruments, water and personnel. This comparison addresses the cost of obtaining and installing the supply. Energy consumption and expected replacement intervals belong in a subsequent operating-cost assessment.
| Item | Define in both quotations | Risk if unresolved |
|---|---|---|
| Membranes | Model, quantity and total active area | Buying different assemblies |
| Accessories | Component list and materials | Incomplete installation |
| Delivery | Destination, packaging and included costs | Extra cost or delay |
| Integration | Adaptations and responsible party | Unplanned site work |
| Acceptance | Method, conditions and result | Disputed performance |
Keep the full denominator behind cost per m²
Suppose one hypothetical offer costs EUR 20,000 for 1,000 m² and another costs EUR 24,000 for 1,200 m². Both equal EUR 20/m². That does not establish commercial equivalence: accessories, transport and the number of components still need checking. If the second requires a frame modification, the area-based indicator omits that work. This is an arithmetic example, not a market-price estimate.
Do not translate membrane area into production without an agreed technical basis. More area may come with a different sustainable flux, wash requirement or feed limitation. For supplies serving the same duty, add the required net output and the conditions assumed by each supplier. Where evidence is incomplete, compare the purchasing scope first and record performance validation as an unresolved condition.
Compare delivery milestones and support conditions
Distinguish manufacture, factory dispatch, arrival at destination and readiness for installation. Identify the event that starts the lead time and any approvals or payments on which it depends. Confirm the delivery point, unloading arrangements and preservation requirements if the plant postpones its outage. A dispatch date does not establish that modules will be installed and available for production on that date.
Read the agreed warranty alongside the incident-support procedure. State the remedy included and who is responsible for transport, removal and installation where applicable. Establish the starting date, required records and support during diagnosis. This review turns commercial conditions into defined responsibilities, while expected service life is evaluated against the actual operating conditions and maintenance programme.
Approve a traceable comparison before ordering
Return the same clarification sheet to each supplier. Retain dates and revisions: a lower price may accompany a change in quantity or support. Record the comparable purchase amount, the differences being accepted and any conditions that must be resolved before delivery. Purchasing and operations should approve the same version rather than working from separate email interpretations of the offer.
Keep separate lines for delivery acceptance and service testing. Receiving ten undamaged modules does not establish that the train meets production duty. Agree who checks documents, when installation is released and what measurements follow. A clearly defined order makes a deviation discussable as a specific issue instead of requiring everyone to reconstruct what complete supply was meant to include.
Common questions
Is the lowest price per m² the best offer?
Not necessarily. Establish a comparable basis for area, accessories, delivery, integration and required service first.
Does a long warranty establish membrane life?
No. Review coverage, starting date, required conditions and excluded costs. Actual service life also depends on the application.
Can we buy modules and install them ourselves?
That scope can be defined, with clear responsibility for compatibility, accessories, installation, testing and records.