Hello,
I am about to replace the RO membranes on the 23G Osmonics. Is there any helpful hints one can give as to going about this task? How difficult? Are there particular areas to be concerned? I do have the 23G manual and will follow steps to a "T". Flush membranes for 8 hrs, etc. DI polish until new AAMI results are posted, etc. Any and all experiences will be greatly appreciated.
Thanks
Ivan

Make G*D**N sure you dont drop any parts in the empty filter vessels by accident during the changeout. Don't ask me how I kmow this.

Make sure the brine seals are in the proper position. Depending on flow in the vessel, some brine seals are on top of membrane and some are on bottom. Replace them one at a time...don't take out all membranes and then put the new ones in. Take one out, put one in..and so on.

Make sure you don't roll the Brine Seals when installing the new membranes (especially for the membranes with the brine seal on the bottom, inserted from the top).

Always replace the O-rings.

Never use pertroleum based lubricants; use water based lubricants if you use any lubricant at all.

I hope you are putting in the correct membrane. "Technically" you are not allowed to install a different membrane without violating the 510k unless the manufacturer has approved that membrane. Some membranes may require an adapter to make them fit in the housing and get the right connections at the top.

I assume you are replacing the membranes due to poor water quality or low flow. Take an AAMI water sample and send it in for analysis before replacing the membranes. If your old membranes are producing high conductivity water, this analysis can be a bounding analysis. If your RO is producing water that meets AAMI at this high conductivity, then you can be reasonably assured it will produce water that meets AAMI at lower conductivities. Always take a sample under the worst conditions and verify you still meet AAMI.

Also, the new Conditions of Coverage specify you must culture weekly for 4 weeks and have them all be acceptable.

Chuck

Thanks for the input. All went well. THe RO Membranes were specific for the 23G from the manufacturer. Did have a bad membrane however. Percent Reject and conductivity were not as good as new membranes should be. Percent reject was around 95-96%.Found the one culprit membrane, took AAMI before and after that one was replaced to cover. Now the percent reject is up to 98.6% with a outout conductivity of 2. Also, placed unit on DI polish until the AAMI results were back.