sunsep™ vs. Nafion™ tubing: a practical, low-risk switch for CEMS & lab users
Nafion™ is a trademark of The Chemours Company FC, LLC.
sunsep™ is a trademark of AGC Inc. (FORBLUE™).
The quick take
If you’re evaluating a Nafion™-based dryer/tubing for moisture control, sunsep™ offers an easy, low-risk migration path. Both technologies move water vapor through an ionomer wall; sunsep™ pairs that principle with instrument-grade housings, standard compression fittings, tight leak checks, and straightforward online procurement—so you can stabilize dew point without slowing projects down.
What stays the same (so your data and SOPs don’t change)
- Mechanism: Both Nafion™ devices and sunsep™ modules transfer water vapor only via a water-vapor partial-pressure gradient—no chillers or desiccant regeneration.
- Analyzer integrity: Designed to retain target analytes for CEMS (Part 75/60) and common lab methods (TDLAS/FTIR/GC/electrochemical).
- Vapor, not liquid: Membrane dryers manage vapor, not bulk liquid. Protect with a 5 μm particulate prefilter and an oil-mist coalescer where lubricated machinery is present.
- Purification scope: If your application requires oxygen removal or other gas purification, pair the dryer with the appropriate downstream treatment.
Where sunsep™ differs in practice
Hardware for instrument service
- Stainless/engineered-polymer housings with clean internal flow paths
- Standard compression fittings for simple drop-in installation
Analyzer stability
- Compact internal volumes and stable pressure drop help optical benches and electrochemical cells settle quickly after zero/span and through load changes.
Easy procurement & support
- Core sunsep™ SKUs are available for direct online checkout with datasheets and model-specific sizing guidance on each page.
- Fast engineering support for cross-references, purge tuning, and installation best practices.
Side-by-side at a glance
| Topic | Nafion™-based devices | sunsep™ |
|---|---|---|
| Moisture-removal principle | Ionomer membrane; vapor transfer only | Same |
| Analyzer behavior | Low dead volume when sized correctly | Compact volumes; predictable ΔP; quick settling |
| Housings & interfaces | Vary by model/vendor | Instrument-grade housings; standard compression fittings |
| Purge setup | Model-dependent; can require tuning | Model-specific guidance; we help trim for seasons |
| Availability | Commonly via reps/distributors | Direct online checkout + engineer review |
(Ask us for a one-page cross-reference; we’ll map your current tubing/module to an equivalent sunsep™ part and provide a purge starting point.)
A few realities that make switching straightforward
1) Temperature behavior
Warmer modules can shorten time-to-dry initially, while cooler modules can reach a lower equilibrium dew point. Place the dryer where it stays within rating and avoid hot spots; insulate upstream lines if cooling would cause re-condensation.
2) Ratings matter (for all ionomer membranes)
Verify temperature and pressure limits for your exact module and location in the system. Some ionomers swell when hydrated—use instrument-grade fittings and proper support where applicable.
3) PDP vs ADP
Specify target Pressure Dew Point (PDP) at line pressure. If you’re comparing specs given at ambient conditions, convert to Ambient Dew Point (ADP) to avoid apples-to-oranges sizing.
4) Hydrogen applications
If purge contains hydrogen (e.g., anode recycle or post-generation polishing), route discharge per applicable safety guidance (classified areas, ventilation/dispersion, flare/recovery as required). We can provide standard venting approaches.
How to switch in under an hour
- Capture current conditions: flow (SLPM), pressure (psig), gas temperature, target dew point (PDP).
- Select the sunsep™ model that covers your flow/pressure with margin—ask for our cross-reference if you’re coming from a Nafion™ part.
- Set purge per model guidance and verify with a dew-point meter. We’ll provide a starting point for your flow/pressure/temperature and help you trim for seasonal swings.
- Protect the membrane: 5 μm prefilter (and coalescer where needed). Keep liquids out; membranes are for vapor.
- Place it smartly: avoid hot cabinets; keep Tinlet ≥ Tambient to prevent re-condensation upstream; insulate as needed.
- Leak-check like an instrument: proper compression fittings and sensible torque.
Application notes
CEMS (EPA Part 75/60)
Stable dew point prevents dilution/adsorption that can disrupt linearity, CGAs, and RATAs. Low internal volume helps optical benches and electrochemical cells settle quickly after span/zero.
Lab & analytical (TDLAS/FTIR/GC)
Controlling humidity reduces baseline wander and water-line interferences in optics and cuts carryover in GC paths—without the footprint or maintenance of refrigerated dryers.
A note on hydrogen crossover
In correctly designed systems, hydrogen crossover through the ionomer wall of a sunsep™ device is very small for normal sizing/stoichiometry. If you operate at atypically high ΔP or need a quantified mass balance, we’ll provide application guidance and data.
Clear boundaries (so expectations are crisp)
- Over-temperature / over-pressure: keep within module ratings or relocate/cool upstream.
- Ultra-low PDP at high temperature: may require increased purge or post-cooling to boost driving force.
- Bulk liquid or heavy aerosols present: add a knockout and coalescer upstream; membranes are not liquid separators.
Ready to compare or buy?
- Shop sunsep™ dryers and humidifiers—add to cart and check out when you’re ready.
- Not sure which model? Send your flow, pressure, temperature, and target dew point; we’ll reply with a right-sized recommendation plus a purge starting point.