Shelf life of watermaker membrane

How long can I store an unopened membrane? My current membranes are at least 5 years old and while they still worked fine a couple of months ago when I last used the unit. I’ll be in the Bahamas for the winter and am considering taking replacements for spare parts. My intention is to use the current pair until they fail and replace, I just don’t want to spend a boatbuck on something that is perishable in storage.

The unit is a Sea Recovery Aquamatic 30 gph/720 gpd system.

I’ve stored a membrane for 3 years. I’ve also lost one that was 2 months old when I chafed a pin hole in the packaging. The membrane dried out and was destined for the dumpster.

You could use the new membranes and pickle/package the old ones and enjoy the higher performance.

Larry is probably right on the shelf life and the manufacturer could confirm it.

A question on changing the membrane in the boat...you mentioned you were headed for the Bahamas. I have a Village modular unit and changed the membrane a couple years ago. I removed the pressure vessel from the boat and took it home to my shop so I'd have the benefit of a work bench. Even then, the end caps are a very tight fit and must be precisely aligned on reassembly. Your Hatt is much bigger than mine, so you must have the access/ room to do it on the boat?

Good question. I’ll take a closer look and see what I’ll need for the job. I have a couple of chain type strap wrenches and a small vise that I hoped would do the trick. If not I’ll have time to get what I need.

It's mostly access and room to work. In my case, no special tools were required. But realizing that the pressure vessel has to withstand 850 psi, the fits are very tight and precise. Hard to get the end caps off, no picnic to get them back on and aligned, keeping the O rings positioned right. None of the foregoing is impossible, just not easy at least for me.

Thanks for the tips. I have a work bench with vise in the stb engine room to do the work. I was a motorcycle fork and shock tech in another lifetime revalving racing suspension so I’m not unfamiliar with that kind of thing. I’ll check my documentation for service instructions or a parts diagram. I assume I’ll need an o-ring kit too or do they come with the membranes like they do with Racors?

With my membrane, the O rings were included along with a tube of lube.