Installation Do’s & Don’ts for Membrane Gas Dryers (CEMS & Lab)
Do’s (best practices that prevent callbacks)
Do protect the membrane.
Install a 5 µm particulate filter upstream; add an oil-mist/coalescing filter if compressors or lubricants are in play.
Do control temperature deltas.
Keep T-inlet ≥ T-ambient to avoid in-line re-condensation before the dryer. Insulate long runs; avoid cold spots.
Do set and verify purge.
Start near 10% purge ratio, then trim to hit target dew point under peak and typical loads. Log values on startup.
Do mount for serviceability.
Leave room to access fittings and filters. Label purge and process ports clearly to prevent cross-connections.
Do leak-check like an instrument.
Use proper compression fittings, torque sensibly, and helium (or appropriate) leak-check where required.
Do plan your venting.
Route purge exhaust to a safe location or abatement; avoid feeding purge back into the sample path.
Do add an outlet PRV if needed.
On systems with downstream pressure spikes, a small PRV (or flow control) on the outlet protects the module and keeps performance consistent.
Don’ts (common mistakes that ruin performance)
Don’t send liquids into the dryer.
Membranes handle vapor, not slugs. If you have condensate risk, trap and heat-trace upstream.
Don’t guess the purge line.
“Looks about right” leads to wet breakthrough. Measure it (rotameter or mass-flow) and record it.
Don’t overtighten fittings.
Instrument components ≠ pipe headers. Overtightening can distort ferrules and create leaks.
Don’t create cold loops.
Routing the sample through a cold cabinet after drying invites re-condensation. Keep the path warm/insulated.
Don’t ignore compatibility.
Aggressive solvents and acids can shorten membrane life. If in doubt, ask for a compatibility check.
Don’t skip documentation.
Log inlet/outlet dew point, purge ratio, flow, and temperature at commissioning. You’ll thank yourself at audit time.
Startup checklist:
- Prefilter installed (5 µm) ± oil-mist coalescer if needed
- Lines inspected: no low spots that trap liquid
- T-inlet/T-ambient checked; insulation applied where needed
- Purge connected, measured, and recorded (initial setpoint: ___%)
- Outlet dew point verified under zero/span and typical load
- Purge vent routed to safe location/abatement
- Leak-check complete; fittings labeled
Troubleshooting quick table
| Symptom | Likely cause | Quick fix |
|---|---|---|
| Outlet dew point too high | Purge too low; membrane fouled; liquid ingress | Increase purge, verify filters, check for condensate upstream |
| Intermittent wet breakthrough | Temperature swings; purge drifting | Insulate lines; stabilize/measure purge |
| Excess pressure drop | Clogged prefilter; kinked tubing; overspeed flow | Change filter; inspect lines; confirm rated flow |
| Slow analyzer recovery | Large dead volume; cold downstream lines | Shorten/streamline tubing; insulate cabinet |
Need a quick look at your P&ID or photos before you go live? Send them with your target dew point and we’ll mark up a sunsep™ installation plan. Request help!