Liquid in a gas flow instrument FAQ
Gas flow controllers and meters are designed to flow only gases, but accidental liquid ingress into a gas flow device can happen in most environments. Depending on the specific flow devices at hand, liquid ingress may be a minor inconvenience, or may result in requiring a whole new set of devices.
Here, we explain what to do when liquid gets into your Alicat device. We also present a case study demonstrating how two gas mass flow technologies, thermal and differential pressure based (DP), respond to liquid ingress.
What to do if liquid gets into an Alicat DP gas flow instrument
- If you notice liquid ingress into your Alicat meter or controller, don’t delay. While liquids will not harm the electronics or sensor in you flow device, they may cause the dissimilar metals to interact if left inside too long.
- If possible, put the device under vacuum conditions. We recommend a hard vacuum (0.25 PSI or less) and some gentle heat (50° to 60°C), to ensure all liquid will evaporate out of the small channels in your instrument.
- If the liquid has suspended solids, flush the device with isopropyl alcohol. Liquid solutions may leave residues as they dry or evaporate, and any grit which is left in the flow path may interfere with the laminar flow conditions needed for accurate measurements. Flushing the device with alcohol will ensure there are no leftover particulates.
- If solid particles have interfered with the laminar flow elements, return the device for servicing. Our service department can disassemble, clean and recalibrate a device for you. If you need service, request a return authorization.
- If you’re worried about liquid ingress, choose your device accordingly. Anti-corrosive meters and controllers are made with 316L stainless steel components, selected specifically for their corrosion resistance with the highest degree of tolerance for liquids. If liquid ingress is becoming liquid flows, it may make most sense to switch to liquid flow meters and controllers.