Help: Air Leak in RO

[Ghs57]

At the end of last season, I noticed air bubbles in the hose between the filter housing and the high pressure pump. They may have alway been there, but I did not notice until I was trying to find out why the Procon pump was so noisy. I assumed I had a leak in the filter housing, so I bought a replacement. The new one is stainless steel, the old was plastic. We put it on this season (using the original hoses), only to find that there are still air bubbles in the line between the filter housing and the Procon pump. This is baffling. All fittings appear tight, including the filter housing O ring and hose connections.

Questions then: Do these Procons normally buzz (sometimes quite loudly) when running under pressure? I don't think it should. When the pump runs with a pressurized water source, like a garden hose, there is no buzz, and it seems that there are no air bubbles in the line. Does anyone else had a similar situation, or an explanation of what's going on?

Thanks.

[maple flats]

They do seem to always make noise. Get a CDL leak finder or other leak finder, it will pinpoint the leak even with the noise.

[wnybassman]

Since I had my RO, my ProCon made a ton of noise. It imploded last year and I replaced it with another brand of pump that is rated just a little more than my old ProCon. The new one is VERY quiet. At 200 PSI it virtually makes no noise.

[Ghs57]

They do seem to always make noise. Get a CDL leak finder or other leak finder, it will pinpoint the leak even with the noise.

I have an idea for tomorrow: I will dismount the filter housing (leaving the hoses attached) and submerge it in a bucket of permeate, then run the pump. if there is an air leak in the housing or the connections or hoses, and if it's under water, the bubbles will stop. I would have done it today, but I just finished an 8 hr boil.

[Ghs57]

Since I had my RO, my ProCon made a ton of noise. It imploded last year and I replaced it with another brand of pump that is rated just a little more than my old ProCon. The new one is VERY quiet. At 200 PSI it virtually makes no noise.

Yes, I've had two fail. What's your new model? I would love this to be quiet(er).

[wnybassman]

Yes, I've had two fail. What's your new model? I would love this to be quiet(er).

To be honest, I have no idea. I bought it from a local maple dealer late last season. Only sticker on it says "MP 350". Can't find it online anywhere. A couple weeks ago I bought a second one from him to have sitting on a shelf......you know............to guarantee I never need it. lol

[Ghs57]

To be honest, I have no idea. I bought it from a local maple dealer late last season. Only sticker on it says "MP 350". Can't find it online anywhere. A couple weeks ago I bought a second one from him to have sitting on a shelf......you know............to guarantee I never need it. lol

I just watched a Smokey Lake RO video for their Mempro 350H RO system, and what to you know, the high pressure pump is the same as the one you describe. It just has a MP 350 label on the end. Looks a lot like a Procon. It also ran quiet. Possible manufacturer is MemProTec.

[wnybassman]

I just watched a Smokey Lake RO video for their Mempro 350H RO system, and what to you know, the high pressure pump is the same as the one you describe. It just has a MP 350 label on the end. Looks a lot like a Procon. It also ran quiet. Possible manufacturer is MemProTec.

That sounds familiar. Definitely looks just like a ProCon with a different label on it, and that MP 350 sticker right on the round part of the pump like the video. Quick Googling and I still can't find one though. lol

[Arctic Fox]

I experienced a situation very similar to yours and it happened at the end of last season for me as well. I'm guessing the pump was experiencing cavitation. I'm going to try using a feed pump to my Procon and see if that solves the issue. I should have some results by tomorrow to report on.

[Ghs57]

I experienced a situation very similar to yours and it happened at the end of last season for me as well. I'm guessing the pump was experiencing cavitation. I'm going to try using a feed pump to my Procon and see if that solves the issue. I should have some results by tomorrow to report on.

I'm very interested in your results. Also, what are you using for a feed pump? I am adding a second post to my RO, and will be adding a booster pump, but have not decided on one yet. I would like it to run on 240v, but haven't found one that's within the budget. Working with some other Mapletraders, and my electrical engineer friend, we have designed a control panel with switching for both motors, a low pressure shut down, recirc and concentrate/permeate flow meters. Pretty standard features on most ROs, but not on budget/entry level systems.

Also, my under water test of the filter housing did not completely solve the air bubble issue. While they were reduced, they were not eliminated. When removing the housing from the water bath, there was a noticeable plug of air sucked through the pump. I let it run for 10 minutes or so to clear the air in the lines. There were no detectable bubbles in the feed line, but very detectable bubbles in the line between the housing and the pump, both in and out of the water bath. This may be helped by the feed pump.

[Arctic Fox]

I did add a Goulds SS 1/2 hp jet pump as a feed pump today, and my wash and rinse worked well on the RO with no weird noises from the Procon, and no bubbles between the prefilter and the Procon. Hopefully this information helps.