Where it fits
A pleated cartridge needs more than its membrane: an outer cage protects the pleated membrane, an inner core supports it from inside and lets the filtrate out, and end caps and adapters are heat-welded to both ends so the cartridge can seal in a housing. For an all-fluoropolymer cartridge with no PP or metal on the wetted surface, this hardware has to be PFA as well. For what each part does, see liquid filter cartridge structure explained.
This series supplies all-PFA hardware to cartridge manufacturers and to equipment builders who assemble their own fluoropolymer cartridges: complete part sets for Ø69 and Ø83 liquid cartridges, Ø28, Ø17 and Ø14 supports and end caps for specialty gas filters, and end caps for high-flow cartridges.
Key characteristics
- Complete part sets: the Ø69 range has an outer cage (Ø68), inner core, 222 adapter, 226 adapter with bayonet lugs, closed end cap, open end cap (adapter ring) and fin end cap; the Ø83 range is the same apart from the 226 adapter, with a 3 mm cage wall.
- Two resin grades: Ø69 and Ø83 parts come in an ultra-pure grade from a leading international brand or a cost-effective high-purity grade. Choose ultra-pure for cartridges used in semiconductor wet processing, and high-purity for general chemical and process-liquid filtration at lower cost.
- Small diameters for specialty gases: a Ø28 outer cage, inner core and closed and open end caps, plus Ø17 and Ø14 one-piece supports, all in the ultra-pure grade, for the small cartridges used in specialty gas filters.
- High-flow end caps: closed and open end caps for high-flow cartridges, in the high-purity grade.
Choosing between options
Decide the cartridge diameter first, then choose the ends to match the housing connection:
| End style | Use |
|---|---|
| 222 adapter | Double O-ring plug-in that seals into the housing head; the most widely used |
| 226 adapter | Double O-ring plug-in with two bayonet lugs that lock with a twist, so line pressure cannot push it out |
| Fin end cap | Closed end of a single-open-end cartridge; the fin bears against the bowl and keeps the cartridge centred |
| Closed end cap | Flat closed end of a single-open-end cartridge |
| Open end cap | Ring-shaped end cap with a central opening, used at the open end of the cartridge |
Choose the resin grade by what the finished cartridge will be used for. Confirm the lengths, inner diameters and mating tolerances when enquiring; if you have your own drawings, send them for comparison. Temperature, pressure and chemical ratings belong to the finished cartridge once the hardware is welded to the membrane; for material selection, see the chemical compatibility guide. If you need an assembled fluoropolymer cartridge rather than parts, see the semiconductor-grade all-PTFE cartridge.
Operation & change-out
PFA hardware is heat-welded to the membrane and support layers. Unpack the parts in a clean environment and avoid touching wetted surfaces with bare hands; store and issue the ultra-pure and high-purity grades separately so they are never mixed.
For a newly developed cartridge, run a small pilot batch first to confirm weld strength, fit and integrity-test results before moving to volume production, and re-check the welding conditions whenever you switch resin grade.