Two quotations labelled “1 m³/h reverse osmosis” can cover different equipment and different operating conditions. First confirm whether the figure means product-water flow or feed flow. Define the intended use: ingredient water, equipment washing and process makeup need a more precise target than the word “pure”.
Define what will be accepted
The enquiry should identify product-water requirements, sampling location, test method and operating conditions. For drinking or food-contact applications, the project owner must confirm applicable local requirements. Keep equipment acceptance and suitability for the intended use as separate evidence. A factory test certificate does not replace testing at the actual point of use.
Understand the flow balance
For an illustrative product flow of 1 m³/h and an assumed recovery of 60%, feed flow is approximately 1 ÷ 0.60 = 1.667 m³/h. Concentrate flow is approximately 0.667 m³/h. This illustrates mass balance; it is neither a recommended recovery nor a specification for a system offered by this website. Actual recovery depends on feed analysis, membrane configuration and design constraints.
Eight hours of theoretical continuous production would yield 8 m³. That calculation excludes flushing, downtime, maintenance and changing demand. Ask how the quoted capacity relates to the available operating window and storage arrangement. Multiplying nominal hourly output by 24 is not sufficient to establish usable daily supply.
| Comparison item | What the quotation should state |
|---|---|
| Feed conditions | Analysis version, temperature and design envelope |
| Product conditions | Targets, stabilisation conditions and sample point |
| Equipment scope | Pretreatment, skid, tanks, piping, controls and instruments |
| Site utilities | Water, electricity, drainage, space and interface ownership |
| Operating cost | Assumptions for utilities, consumables, cleaning and labour |
| Acceptance and support | Procedure, warranty conditions and service scope |
Ask suppliers to turn claims such as “zero wastewater” or “works with every source” into measurable statements with defined conditions. An omission should remain an open question, not silently become part of the assumed supply scope.
Use staged site acceptance
Start with model numbers, quantities, nameplates and accessories. Then inspect connections, leaks and protective functions. Finally record flow, pressure and agreed water-quality indicators under the defined feed and operating conditions. A responsible person at the site should verify sampling and operation; a video call does not replace every local duty.
If actual feed conditions fall outside the agreed envelope, document the difference and agree on a valid retest. Use the industrial RO enquiry guide to prepare missing information. Transport, import, installation and local compliance responsibilities belong in the project agreement.
Source: DuPont FilmTec technical manual. AI-assisted purchasing guidance. The numerical example is hypothetical and is not a Vietnamese delivery case.