Define the treatment duty before selecting an RO skid
A reverse osmosis proposal becomes comparable only when feed-water variation, finished-water targets, net production demand and every supporting utility are stated on the same basis.
Direct answer
Begin with representative raw-water analysis and the approved product-water specification, then calculate the net treated-water demand from filler consumption, operating hours, sanitation use, losses and storage strategy. Ask each supplier to state pretreatment assumptions, membrane duty, design recovery, permeate flow at declared feed conditions, reject-water route, clean-in-place boundary, instruments, consumables and utility loads. The selected system must also connect reliably to hygienic storage and the filler feed. Acceptance should therefore compare defined water-quality measurements and stable net flow at agreed conditions, not a pump nameplate or an unqualified membrane rating.
System focus 01
One laboratory result is not automatically a design envelope. Collect samples that represent relevant seasons, wells, municipal supply changes or blending arrangements, and record sampling location and date. The analysis should cover the parameters needed to evaluate scaling, fouling, oxidation, membrane compatibility and product treatment objectives. Where a value varies, give bidders a range rather than a convenient average. Suppliers should identify any missing test that prevents final selection and should distinguish assumed values from confirmed data. This makes pretreatment choices and operating limits traceable instead of hiding them inside a generic RO package.
System focus 02
The filler bottle-per-hour rating does not directly equal the RO flow. Convert the product plan into water volume by bottle format, realistic scheduled hours and the expected operating pattern. Add defined water users such as product change, start-up flushing or an agreed sanitation demand, while keeping unrelated factory consumption outside the product-water duty. Storage can decouple treatment and filling for a limited period, but it does not create daily capacity. Ask for a balance showing gross feed, permeate, reject and auxiliary streams at stated feed temperature and composition so each quotation uses the same net-output basis.
System focus 03
Pretreatment must respond to the actual feed-water risks and the selected membrane limits. A process may include oxidation control, clarification or filtration, hardness or scale control, cartridge protection and chemical dosing, but the correct sequence is project-specific. Request the basis for each stage, expected inlet and outlet condition, monitoring point, consumable and disposal stream. The proposal should define how membranes are isolated, flushed and cleaned, what cleaning equipment is included, and which chemicals remain the buyer's responsibility. Maintenance access for filters, pressure vessels, valves and sampling points belongs in the equipment review.
System focus 04
Permeate quality can change after the membrane if storage, vents, piping or stagnant branches are poorly integrated. Define the RO outlet connection, tank inlet arrangement, recirculation concept, final treatment if specified, filler-feed pressure and the operating response when either the RO or filler stops. Materials, drainability, sampling access and cleaning boundaries should be reviewed for the product-water zone. Control signals must prevent the RO from cycling on every small level change while also protecting pumps and preventing tank overflow. The interface schedule should assign the tank, pumps, instruments, valves, cables and interconnecting pipework to named supply scopes.
System focus 05
A useful request for quotation asks for a process description, flow balance, equipment list, instrument list, utility schedule, consumables, exclusions and recommended maintenance items. Factory testing can verify assembly, controls, alarms and simulated operating sequences, while water-performance evidence may require suitable feed water and calibrated measurements at site. Agree the sampling method, stabilization period, instrument accuracy and treatment conditions before testing. Record permeate and reject flows together with relevant quality readings and feed conditions. Final acceptance should not imply that one short test proves every seasonal source-water condition unless that range was specifically represented and agreed.
RO inquiry comparison matrix
Use this matrix to expose assumptions before comparing skid size, membrane count or commercial scope.
| Decision input | Buyer should provide | Supplier should return | Acceptance boundary |
|---|---|---|---|
| Feed-water envelope | Representative analysis, variation and sampling context | Missing-data list and declared design range | Test conditions recorded with results |
| Product duty | Target specification, net demand and operating schedule | Permeate flow and quality basis at stated conditions | Named outlet point and measurement method |
| Pretreatment | Available upstream processes and chemical constraints | Purpose, sizing basis, monitoring and residual risk | Stage checks against agreed inlet conditions |
| Membrane train | Required availability and operating philosophy | Array, recovery, operating limits and protection logic | Stable operation within declared feed envelope |
| Cleaning and consumables | Site safety rules, storage and disposal constraints | Included equipment, initial supply and replacement schedule | Functional sequence and handover records |
| Storage and filler feed | Tank concept, filler demand and interface locations | Hydraulic, signal and responsibility schedule | Integrated site trial with representative demand |
Final configuration and acceptance values remain subject to confirmed source water, product requirements, equipment selections and project-specific test conditions.
Buyer questions
Use these answers as a project-planning starting point. Final equipment and performance remain subject to the confirmed brief.
No. Total dissolved solids is useful but does not describe all scaling, fouling, oxidation or pretreatment risks. A selection should consider a representative analysis, variation over time, temperature, target product specification, flow duty and the selected membrane supplier's operating limits.
Not necessarily. Net water available depends on stated feed conditions, membrane condition, treatment availability, flushing or sanitation consumption, storage level and the filler schedule. Ask for a complete water balance and define the measurement point used for acceptance.
No. Recovery is constrained by feed-water composition, pretreatment, membrane arrangement, concentrate management and the operating strategy. A higher stated recovery can increase concentration and scaling risk, so it should be justified by a calculation rather than treated as a universal target.
Clarify the cleaning tank, pump, heater if required, filters, hoses or fixed piping, chemical mixing, isolation, drain route, procedures, safety controls and initial consumables. The final method and chemistry must follow the confirmed membrane, deposit risk and site safety review.
Deep technical guides
Each guide answers one narrower project question and links the result back to complete-line scope.
Water softening upstream of RO is justified by hardness loading, membrane recovery, scaling calculations and the complete pretreatment strategy. Resin capacity, vessel duty, brine system and regeneration controls must support the actual production and reject-water plan.
RO antiscalant selection begins with a complete feed-water analysis, recovery and concentrate chemistry. The chemical, dose and control strategy must be compatible with membranes, pretreatment and the approved product route, and cannot be chosen from a generic dose range.
RO cleaning should respond to normalized evidence of fouling or scaling and use a membrane-compatible procedure matched to the likely deposit. Cleaning too late can make recovery difficult, while unnecessary cleaning adds chemical exposure and downtime.
Capacities, process routes, layouts, utilities and equipment shown on this site are decision frameworks and reference examples. They are not a final specification, performance guarantee or offer. Confirmed scope and performance are defined in the signed technical and commercial agreement.
Allot Tech project desk
Share the source water, bottle, target output, pack format, factory status and destination. We will use them as the basis for a project-specific configuration discussion.