Float valve

[JeffP104]

Does the use of a float valve connected to the RO/DI unit for automatic top-off cause premature wear on RO/DI unit filters or other components?

Thanks

[SpectraPure]

We do not recommend the use of float valves with automatic shut-off valves (ASO) for evaporation replenishment. These ASO valves are designed for use with bladder tanks like the ones used in RO drinking water systems. When used with just a float, they cycle on and off very frequently which results in high TDS water produced by the membrane (TDS Creep), significantly reducing the life of the downstream DI cartridge. Also, there is no redundant backup float for protection from flooding or a drop in salinity. A much better solution for top-off is our electric liquid level controller (LLC-S-120 (http://spectrapure.com/St_alc_p1.htm)). It allows the RO system to operate much longer between cycles and uses the now redundant mechanical float as a secondary safety shut-off in case the primary level control fails. If a float valve/ASO combination must be used, it is much better to use a smaller RO membrane to increase the run time, eliminating the on and off cycling of a large membrane.

Charles Mitsis
President SpectraPure Inc.

[JeffP104]

That is consistent with feedback on other RC forums.... I just wanted to hear it directly from the manufacturer.

Thanks for the response.
JeffP

[ScottC]

I'll back up that statement as well. We use the SpectraPure LLC on every top-off system we install, and as a back-up we put a float in just a little higher than the LLC...just in case! I still have not seen a LLC fail in over 300 systems. It's easy to install, and gives a little peace of mind.