A membrane replacement starts with the operating system, not only the label on an element. The model, feed water, pressure vessel and required permeate quality form one selection problem. Use this guide to prepare a new-system enquiry or a replacement request and to separate catalog test values from the performance your site actually needs.
Choose the family from the feed water and treatment task
Begin with a water analysis and the purpose of the RO stage. BW products address brackish-water applications, ULP products provide a lower-pressure option for suitable lower-salinity feed water, FR products are offered for fouling-sensitive enquiries, and SW products address seawater duties. These family names narrow the discussion; they do not establish that a particular model will meet your project conditions. Record seasonal temperature and salinity, pretreatment, required permeate quality and the available pump operating range.
For reuse-water applications, include suspended solids, organic loading and the history of pretreatment and cleaning. A fouling-resistant membrane still needs appropriate operation and monitoring. For seawater, state any boron requirement separately from conductivity or total dissolved solids. Final water treatment and verification remain part of the complete system design.
Keep every flow and rejection figure with its test conditions
The BOKAWATER BW-8040 and ULP-8040MR-2 listings both show 10500 GPD, but their test points differ. BW-8040 is listed at 225 psi with 2000 mg/L NaCl, while ULP-8040MR-2 is listed at 150 psi with 1500 mg/L NaCl. Treating these two numbers as an identical operating guarantee would omit information needed for selection. Compare test pressure, solution, temperature, pH and recovery alongside active membrane area and salt rejection.
Do not multiply a single-element catalog flow by the installed element count and present the result as guaranteed plant production. Feed conditions change through the array, and the proposed system needs its own performance projection. Ask the supplier to state feed assumptions, design recovery, product-water target and the conditions attached to any guaranteed duty.
Confirm mechanical fit and prepare the replacement enquiry
Record the complete installed model and manufacturer, element count, vessel arrangement and connection details. Confirm element dimensions, product-water tube, adapters and seals from the actual equipment documents. Similar model numbers are useful search terms, but they do not certify compatibility. For an operating plant, also provide measured flow, conductivity, pressures and the dates of recent cleaning or replacement.
An enquiry should identify the requested quantity, delivery destination, intended installation date and any documentation needed by the operator. Use the product-specific enquiry button to carry the BOKAWATER model into the request, then add the existing model and water data. Ask for a configuration-specific proposal and agreed acceptance checks before ordering.
Data to collect before comparing proposals
| Parameter / interface | Unit / format | Why it matters |
|---|---|---|
| Existing model and manufacturer | Nameplate / model | Identifies the installed reference without assuming equivalence. |
| Element and connection dimensions | Drawing / dimensions | Checks vessel, adapters, product-water tube and seals. |
| Feed-water analysis and temperature | Report / °C | Defines the water conditions for a system projection. |
| Permeate duty and quality target | m³/h / specification | Separates the required system duty from catalog element flow. |
| Array, pressure and operating history | Layout / pressure / records | Supports hydraulic review and diagnosis of existing performance. |
| Element quantity and delivery | Pieces / destination | Defines the supply quantity and shipping requirement. |
| Pretreatment and cleaning history | Process / service records | Supports fouling assessment and an appropriate operating plan. |
Technical references
- BOKAWATER BW-8040 specifications and test conditions ↗
- BOKAWATER ULP-8040MR-2 specifications and test conditions ↗
- BOKAWATER SW-4040 membrane specifications ↗
Prepared with AI assistance from the references below and original project-planning checklists. General engineering guidance; project specifications require confirmation by the responsible engineer.