How Swing cartridges work
A Swing-8 cartridge holds 114 sheets and about 135 ft² (12.5 m²) of membrane; a Swing-9 holds 208 sheets and about 250 ft² (23 m²). Modules are built from decks and columns of cartridges. When a section is damaged or fouled beyond recovery, that cartridge comes out and a fresh one goes in. A full module breakdown takes roughly two hours.
Hollow fiber, typical flat sheet and Zyramic cartridges
How the three approaches generally compare in service:
| Feature | Hollow fiber | Typical flat sheet | Zyramic cartridge (Swing) |
|---|---|---|---|
| Replacement | Whole bundle or module | Full panels or cassettes | Replace a cartridge quickly: swap one small cartridge in minutes without pulling the whole module |
| Owner maintenance | Bundle repair or replacement often needs specialist help | Panels or cassettes usually lifted as a unit | Surface servicing: sheets stay sealed in their small, cost-effective cartridge, so you swap the whole cartridge quickly, in minutes, in-house with basic tools and little downtime |
| Wear and tear | Fibers can break at the potting | Large sheets flex in service | Small sheets flex less, for less wear and tear |
| Edge seals | Potted fiber ends | Varies by design | Strong wide membrane welds, designed to resist delamination |
| Membrane | Thin fibers | Varies | Thick, about 250 microns including support, for robust service |
| Ragging | Hair can wrap fiber bundles | Open channels | Open channels between small sheets |
| Inspection | Bundle examined closely | Panel lifted to inspect | A lifted cartridge shows its condition at a glance |
| Custom sizing | Fixed module sizes | Often fixed sizes | Cartridge and module sizes tailored to your tanks in many cases |
Performance depends on pretreatment, design flux and operation.
Custom sizing: we cut, weld and assemble in Poughkeepsie, NY, so cartridge and module sizes can often be tailored to your existing tanks. Tell us your tank dimensions, or see custom sizes.
Why smaller units help
- Less downtime: service one cartridge without taking the whole train offline for long
- Lower replacement spend: replace only what is worn
- Easier handling: lighter lifts, often without heavy equipment
- Less wear and tear: smaller sheets flex less in service
- Better inspection: operators can see real membrane condition
Stocking spares
Many plants keep a few spare cartridges on the shelf. Swing sheets are permanently wetted and ship and store dry, which makes spares easy to keep. See parts and accessories for cartridge part numbers and membrane life for planning.
| Mild backwash (special cases only) |
|---|
| Backwashing is not a standard Swing operating mode and is not meant for routine use. Swing has been pressure-tested to 14.5 psi (1 bar) and held without breaking. If a site is in a bind even after relaxation and CIP, contact us; we may be able to work out a special mild-backwash procedure. |
Worked sizing example
Take a 52,834 gpd (200 m³/day) plant replacing worn cartridges:
| Item | US | Metric | Note |
|---|---|---|---|
| Average flow | 52,834 gpd | 200 m³/day | about 37 gpm (8,333 L/h) |
| Design flux (gross) | 11.8 gfd | 20 LMH | Zyramic design guidance |
| Derate for relaxation and cleaning | ~20% | ~20% | |
| Net flux | ~9.4 gfd | ~16 LMH | |
| Membrane area needed | ~5,606 ft² | ~521 m² | average flow ÷ net flux |
| Swing-8 cartridges | ~42 | ~42 | 135 ft² (12.5 m²) each |
| Peak factor | ~2.0 | ~2.0 | |
| Peak flow | ~105,669 gpd | ~400 m³/day | extra area, short-term higher flux, or equalization |
This is an illustration only; a real design also checks temperature, MLSS, redundancy and the cleaning schedule.
Tips for a smooth project
- Compare modules on lifecycle, not area alone
- Plan how replacement parts will be sourced later
- Allow room for handling and inspection
- Check cassette dimensions before ordering replacements
Next step
A good way to see which design choices matter most for your plant is to look at your own maintenance history. Tell us what has needed attention in the past, and we will explain which of our options fits it best.
Sizing considerations
To give a useful recommendation we usually need:
- Module model and number of cartridges
- Cartridges needing replacement
- Spare stocking plan
- Lifting equipment available
- Delivery timeline
Most relevant product: Swing MBR. See also replacement membranes, rentals and how to choose.
Why engineers look at Zyramic flat-sheet modules
| Item | Details |
|---|---|
| Smaller sheets, less wear and tear | each sheet flexes less in service, and a damaged unit affects less area. |
| Strong wide membrane welds | designed to resist delamination over the membrane's life. |
| Thick, robust membrane | about 250 microns including support. |
| Assembled in Poughkeepsie, NY | of domestic and imported components. In our Poughkeepsie shop we cut and weld membrane sheets to plates, build module frames and assemble complete modules. For funded projects, tell us your domestic-content requirements and we'll review what we can document. |
| Buy, rent or replace | new modules, rentals and pilots for US projects, and replacement membranes that fit many existing cassettes. |
Performance and life depend on pretreatment, design flux and operation; flux figures are Zyramic design guidance, sized to each project.
Frequently asked questions
Can cartridges be swapped with the tank full?
In many layouts, yes, though procedures depend on the installation.
Do cartridges need to stay wet?
No, Swing sheets are permanently wetted and can be stored dry.
Are cartridges sold separately?
Yes, see parts and accessories or request a quote.
Can I mix new and old cartridges?
Yes, though performance will differ by age.
How many cartridges are in a module?
It depends on the deck and column configuration; a Swing-8-X-Y module holds X times Y cartridges.
Can old cartridges be refurbished?
Ask us. Depending on condition, some components may be reusable.