Help? Spectra Watermaker leaking

[myocean]

Hello together!
I have an acute problem with our Spectra V200T and hope somebody out there can help? We are in midst of Polynesia and need to solve the problem on our own. (have offshore repair kit at hand)
The unit is 15 months old and has about 1000 hours.
Since today it suddenly shows a significant leakage at the membrane housing end cap (high pressure inlet). The water spills out between housing(tube) and the big holding ring used to close the housing.
The product flow is extremely low now.
It has been 6.5-7 gph in the past.
I have now changed the o-ring which is located on the end piece with the fluid connections. (even though the original looked good). Neither the membrane housing tube, nor the holding ring or the end piece with fluid connections shows any cracks. (I don't see anything unusual...)
I can't find an explanation why there is suddenly this leakage. What is the reason for it?
Tightening threads and fittings does not change the situation significantly.
I would be very glad to get a hint!
Yours,
Ulf

[Kenomac]

CF member Tellie should be able to answer your question. Having just rebuilt our spectra and experienced a leaking end cap, I can tell you that there is actually three O rings in there, two small ones which are hard to see. I ended up switching out the entire cap since there was a spare on board. This cleared up the problem. I didn't notice the two small O rings until I looked closely at the new cap just prior to installation. I'd already taken off and replaced the leaking cap three times and was getting impatient when I found the spare. I'll bet its one or both of the smaller O rings causing the leak.

Ours is a model 380c spectra.

[Dulcesuenos]

Sounds like one of the O rings on the endcap. Is your product water good or high salinity now? Have you pulled the endcap and checked or replaced the O rings?

Sent from my LG-LS980 using Cruisers Sailing Forum mobile app

[dlockhart]

If it's the inlet end of the membrane could perhaps the membrane itself be plugged and cause more than normal pressure at the inlet side?
Good luck.

[myocean]

Thanks a lot for your valuable comments!
I will check for the smaller o-rings - great to know what to do next!
I can't imagine why the membrane should suddlenly be that clogged to increase the pressure on the sealings significantly. We are currently in a pristine polynesian lagoon with perfect water quality and we have used the unit a lot since one year without interruptions.
Anyway the membrane needs a clean since quite a while (even though I don't understand why - back pressure has been 90-95 instead of <80 psi) . So I will do that as soon as the system allows me to do it properly without leakages.

[Kenomac]

The membrane shouldn't need to be cleaned. Because of the way it works, the membrane is constantly being flushed with salt water to remove small (very small) debris. Then when you freshwater flush the system, any harder sodium or scale deposits are removed. The membrane doesn't work like a traditional filter, it's more like a long tube that doesn't allow suspended solids and ions to pass through.

Write or call Spectra, the tech is very good at diagnosing problems and explaining how the system works.

[belizesailor]

Yes, Spectra tech support is excellent. Contact them.

Tellie may also repsond here and is very knowledgeable (Spectra Distrubutor).

I agree it sounds like a seal, but a seal should not go bad in such a short time. Maybe another issue causing back pressure?

Wow, 1,000 hours in 15 months? Is that a typo. I've got just less than that on my Catalina 300 after 10 years.

[dlockhart]

i think you stated the answer yourself, back pressure has risen to 90 to 95 in lieu of less than 80. My Spectra runs at around 65 psi so adding 30+ psi I might expect some blow by the o ring. Worth a shot to clean it or replace it.

[Tellie]

If you are leaking water from the membrane tube and the pressure vessel end ring it can only be one of four things. The end cap does have a hairline crack (which can be hard to detect), the membrane vessel has a crack in it (which is very unlikely), the large O-ring on the end cap is bad, or the end cap is not seated properly in to the membrane vessel. I would first check to make sure the end cap is seated properly. You'll have to remove the high pressure line to the end cap. Once the high pressure line is off see if you can turn the end cap by hand. If it moves easily or with some resistance the end cap is not seated. With the heel of your hand bang the end of the end cap into the membrane vessel (you may see or feel it pop in a slight bit). Now try to tighten down the end ring. If it turns a bit then the end cap was not seated properly. You can use a small block of wood placed in the end rings slot and gently tap the wood block to help tighten the rings a bit (don't over do it). Once the end cap is seated properly you should not be able to spin the end cap. Re-attach the high pressure line (with two wrenches of course) This should solve your leaking problem. If it is still leaking look very carefully to make sure the leak is really not at the fitting threaded into the end cap, because it is located so close to the ring it may appear the leak is from the ring when it is not. The slightly higher pressures should not be able to make the end cap leak. These are the same membrane vessels used on much larger Spectra's that create more pressures and flow at the same areas without leaking. The two internal O-rings (the newer models only have one) would not leak externally if they failed. But they would raise the TDS readings significantly. Also what is your total production? Though the higher pressures are something to look at they are not that far out to make a much of a difference. Make sure there is nothing blocking the brine discharge line as well. If this does not stop the leak let me know. Feel free to call me as well if you'd like. (954) 515-7077

[myocean]

Thank you Tellie, great to have you involved here!
So I have checked according to your recommendations:
I am quite convinced to have a decent seating of the end caps. I had always banged them in by hand and now I have additionally used a piece of wood as recommended. Tightening the rings one feels a well defined final position.
Additionally, to make sure it is not a crack in the end ring, I have swapped the two end rings.
The leakage is still there, water squirting out from the thread between vessel and ring on the inlet side, even with the other end ring and with a, I think, nicely seated end cap.
So I have checked the membrane vessel for cracks. Its translucent in the thread area which is why I have "x-rayed" it with a 1200 lumen spot light. There is nothing unusual visible - all nicely homogeneous, no strange reflections or so. It should be ok than, right?
So what can it be? The o-ring I had changed already and as this did not help I have put some teflon tape underneeth to make it a bit thicker. I can certainly take this off again. As said I have changed the end piece o-ring and the end-piece itself looks very sturdy and nice. It can't be that, right?
I am asking myself what can have caused the problem. There was nothing unusual as far as I remember, no shocks or so. (even though we have two kids on board and you never know what they have done...)
Yours,
Ulf


PS: I thought it is too late now to call you... Thank you for the offer!

[myocean]

Here the solution!

For testing I have turned around the high pressure vessel which is actually just a tube with threads and I have found the now the leakage had moved with the vessel - now located on the outlet side.
So the problem IS the vessel. A closer look with this clear knowledge finally revealed the crack which we had not found before! It is located just at the end of the thread close to where the translucency changes to black.
After thinking about putting a tape on it I have now laminated a thin layer of fiberglass fabric with epoxy onto it, on the inside of the vessel. I will have to sand it nicely and hope that the end piece o-ring will still be able to do its sealing job.
Thanks a lot for your help!