A request for a box of RO filter cartridges is incomplete without the installed assembly and approved service conditions. For an enquiry referencing BOKAWATER BK-3000RO, request the order-specific filter schedule rather than inferring it from the equipment name. This guide concerns pre-RO cartridge consumables, not replacement RO membrane elements, and does not declare any third-party cartridge compatible.
1. Make the spare-parts line identify a complete serviceable item
Assign a tag to the filter housing and record its manufacturer, model, drawing revision and cartridge quantity. Ask for the exact installed part number and a dimensioned interface record: effective length, diameter, end arrangement, adaptor, support and sealing surfaces. Include the gasket or O-ring material and any separate kit. A photograph is useful evidence but should accompany, not replace, the supplier's documented part identification.
Parker's example sheet separates dimensions, fittings and seals. Use that distinction to request your own bill of materials; its options do not prove what BOKAWATER supplies. Have the supplier review actual water chemistry, temperature, dosing and any approved cleaning exposure against the proposed media, structural components and seals. Require written review of substitutions before ordering, even where a cartridge appears to fit.
2. Specify a filtration duty instead of a micron label alone
Pall explains why a filter rating needs its test basis. Ask whether the offered grade is nominal or absolute, what retention claim and method accompany it, and the conditions to which that claim applies. Do not translate one supplier's label into another supplier's efficiency. The RO designer should confirm the required protection and the selected grade for the actual pretreatment train.
Request a sizing record showing the flow through this housing, cartridges in service and the predicted clean pressure loss under the stated conditions. Keep RO permeate output separate from flow through the upstream filter. Identify the pressure instruments and the approved limits of the complete assembly. A component strength rating is not, by itself, the operator's replacement trigger or a permitted system pressure.
3. Turn each replacement into an operating record
FilmTec guidance discusses pressure monitoring and cartridge bypass risks. Obtain a site procedure defining warning, changeout and investigation criteria from the actual suppliers. As arithmetic only, simultaneous upstream and downstream readings of 2.6 and 2.3 bar give 0.3 bar differential pressure. This is not a recommended trigger. Record flow, temperature, instrument tags and operating state with the reading so changes are interpretable.
At replacement, retain date, reason, part and batch identity, service time, recorded pressures and the observed cartridge condition. Assign responsibility for safe isolation, inspection of the housing and seals, reassembly and return-to-service checks under the approved manual. If service life shortens sharply or downstream condition worsens, request an upstream and assembly review rather than simply accepting repeated consumption. Keep startup stock separate from normal operating stock; agree quantities and reorder arrangements using actual demand and confirmed delivery information, without promising a universal life or stocking period.
Data to collect before comparing proposals
| Parameter / interface | Unit / format | Why it matters |
|---|---|---|
| Purchasing record | Information to retain | Decision enabled |
| Assembly identity | Housing tag, model, drawing and cartridge count | Identify the installed boundary |
| Replacement item | Part number, dimensions, end fitting and adaptors | Review the complete interface |
| Materials | Media, support, seals and actual exposure | Obtain written suitability review |
| Filter rating | Micron grade, rating type, test basis and retention claim | Avoid unsupported label equivalence |
| Hydraulic duty | Housing flow, cartridge count and clean pressure loss | Check sizing at the stated condition |
| Monitoring | Instrument tags, pressures, flow and temperature | Interpret a comparable differential |
| Service criteria | Approved warnings, changeout and investigation rules | Separate operating action from component strength |
| Replacement history | Date, reason, batch, observations and release check | Trace changes and recurring problems |
| Stock planning | Startup quantity, operating reserve and reorder owner | Base replenishment on actual service demand |
Technical references
- DuPont — FilmTec Technical Manual, 45-D01504-en, Version 20, August 2026 ↗Source checked:
Evidence scope — original English record
Sections 2.5.7 and 8.5.3(a): cartridge protection, differential-pressure observation and bypass risks. FilmTec-specific micron, replacement-time and operating limits are not transferred to BOKAWATER. The purchasing worksheet is original project guidance, not a supplied configuration or operating instruction.
- Pall — Principles of Filtration, WER 5300 ↗Source checked:
Evidence scope — original English record
Filter-rating discussion, printed pages 7–10: a micron label needs its rating and test basis. No universal nominal/absolute conversion or removal percentage is adopted.
- Parker — Polyflow Absolute-Rated Filter Cartridge Data Sheet, 2025 Rev. A ↗Source checked:
Evidence scope — original English record
Example of separate ordering fields for length, end fitting and seals, and conditional differential-pressure limits. No Parker part, rating, certification or compatibility is claimed for a BOKAWATER package.
- BOKAWATER — Advanced Industrial RO System, item BK-3000RO ↗Source checked:
Evidence scope — original English record
Existing equipment item identity only. The public listing does not establish the installed cartridge, housing, seal material, spare quantity or approved changeout criterion for a particular order.