DIGITEN 1/4" Automatic Shut-Off Valve with Quick-Connect Fittings For RO Reverse Osmosis(Pack of 2)

Basic ASO valve, works as expected. Can't speak to the actual pressures that trigger the valve as I didn't measure them, but it seems to be standard. If you have an RO system with a mechanical float in the tank that plugs the output tube and develops backpressure that way (like on an office water cooler), the minimum pressure differential may not ever be reached to trigger the valve and shut off the flow, and it might cause it to flutter or make a loud and annoying buzzing sound. Your RO membrane will continuously pump out wastewater, obviously a major problem. A fix for this is to run the wastewater output through the high pressure side of the ASO valve (side that says In and Out, not the side with the screws) instead of the feed water going into the RO membrane like the typical configuration requires. Wastewater comes out at a lower pressure than incoming city/well water, so the difference between wastewater and clean RO output water will be closer, and the valve will actually open and close quickly like it should. It's not a perfect fix, since running high-TDS wastewater through the ASO valve will make it gunk/mineralize up faster. But they're dirt cheap to swap out, and it definitely beats the hassle of retrofitting a solenoid and electric float switch into a setup that wasn't designed for it.

The Automatic Shut-Off Valve (ASO) is a commonly forgotten component of a reverse osmosis system during normal maintenance such as filter changes. However they do age and wear out, and eventually don't shut off at the right time and consequently waste a lot of water. I purchased these to replace one that had failed - I could hear the water running continuously - and also one as a spare for the next time this part needs to be replaced. Product quality looks good, and after installation I could tell it had shut off the water flow at the right time. Delivery was prompt, I would buy from this seller again.

First of these 2 replacement valves worked fine, stored the spare. Happy with our RO unit about 25 yrs now…install hints?: Cut off water pressures from house and RO tank, and before removing old valve, note the in/out valve end labels, also record the 4 line locations (pic, labels, or notes). Remove small plastic line locking c-clips. To remove lines, push in the locking collars and pull line out. (can also use open end 5/16” or 8mm wrench to help pushing in these quick release collars, saves fingernails). Reinstall lines on new valve, make sure they push all the way in (about ½”), then pull outward firmly to seat. Apply plastic line lock clips. If you have a seating leak afterward, remove the ¼” line, and cut off the line’s end. (seating portion only, it probably has surface scratches seeping). Two notes: #1. You can damage/foul these valves when plunging clogged sink drains. If you need to use a plunger, first remove the sink drain ¼” RO drain pipe hose, then wrap towel/rag around the ¼” drain hole opening to catch those small pressure squirts while plunging your sink drain. #2: Occasional gurgling drain sound when unit is removing the wastewater in normal operation? You can shove the ¼ “drain line into the drain pipe a tad further so it drains down the far inside of the sink pipe, and no gurgle. We prefer to leave line inserted slightly and let normal occasional RO wastewater fall/gurgle somewhat down into drain pipe's water trap. A consistent gurgling when close by the sink will let you know when the valve has finally failed and is wasting water all day. Excessive gurgling sounds because you are using more than your usual needs in filter water? Perhaps you just want to silence it for company coming into kitchen? Put your sink drain plug into the gurgling drain side, that muffles the sound.

This worked perfectly to replace the failed valve in our RO system. Water had been flowing nonstop through the system at 6-9 gallons per hour. Replacing the valve dropped that to next to nothing. Replacing the old valve was easy. Pushing in the collar around the tubing allowed it to be removed from the old valve and easily inserted into the new one. The sides are clearly marked with “in” and “out” so you don’t mix them up. Don’t forget to drain the tank and shut off the water first. The results can be rather spectacular if you don’t….

The ones I got work fairly well. Had a hard time figuring out why they were not stopping the water flow when tanks were full. Then found out I needed a little ball check valve on the membrane output. May have lost it somewhere along the way or my system didn't come with it. I added the tank after I bought the membrane and filtering system so I could have a couple gallons of RO water stored up. Soon as the check valve was installed properly, everything started working the way I needed it to.

I order a whole under the sink RO system with a bunch of electrical components. Then it stopped working after a few weeks. The seller was nowhere to be found. And there was no specs about those parts. So, I decided to turn my fancy RO filter into a Regular RO system. I just needed this valve and a restrictor. Now everything works to perfection. Such a life saver. It outlasted the original setting. Very easy with a picture of another setting.

I find it hilarious that the review is asking me to rate "flavor", I'm not sure I'd like to taste these valves to find out (and rating the water has nothing to do with the valve!). So humor aside, this was my situation: Water was leaking from the airgap in the faucet of my Watts Premier RO Pure+ system. Determined that there was no drain blockage or excess loop. Determined that even after shutting off tank valve, faucet, and ice maker line, system kept filtering water (and creating waste brine) without stopping. Culprit here being the ASO valve, though I had no idea if this would have any affect on the airgap leak. Apparently we'd all tuned out the gurgling noises and thought them normal. I shut off all water to system while I waited for replacement ASO valves. Yay lugging bottled water! FWIW one of my new valves arrived with one of the blue clips floating in the package, no big deal, just make sure you have them all to start. Remove all 4 blue clips. Install tubing in correct orientation, following previous install. Check internet if needed, this valve was pictured but not mentioned in my system's manual. Reinstall blue clips into their previous locations (this involves gently pulling on the tubing until the collets come away from the valve enough to fit the clip). These clips help prevent you from accidentally knocking the tubes out when doing other under-sink things, thus preventing other kinds of leaks. My previous ASO valve did not have them and I was fortunate to not have any leaks from it, but can't be too safe with water imo. With the drain hose detached from the sink drain, I turned the water back on to the filters and tank. Water drained as expected (into a bucket, of course). Turning off the tank valve showed the valve worked, the filters stopped draining water as they should. Huzzah! Checked faucet - no leak (yet?) - reassembled drain, opened valve to tank, let everything refill. Waited. No leaks! Huzzah again! Apparently a faulty ASO valve and the constant draining must cause enough pressure to build up in the line into the faucet causing the airgap to leak water. This isn't a common issue apparently, and 99% of troubleshooting tells you other problems can occur due to a faulty ASO but never mentions water out of the airgap. Hope this helps someone else!

My Watts RO-PURE was installed April 2011 and has operated flawlessly, that is until recently, when I noticed the drain line was running constantly. Referenced several YouTube videos to diagnose this problem. With water supply on/tank valve ball valve on or off, water flowed to the drain saddle. However, with water supply off/tank ball valve on, no water flowed into the drain line, indicating a faulty automatic shut off valve. The valve was easy to replace and this part fixed the issue, for less than 1/2 the cost of a replacement valve sold by the manufacturer. Highly recommend.