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

Product works fine

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.

Doesn't come with any instruction on how to install this so it was a little confusing. I basically connected the clean water on the top connection and the waste water on the bottom so when my float valve cuts the flow, the clean the waste water gets auto shut off. I would have rathered I was able to connect my water in line instead of the waste water line, that way I could auto shut off water to my entire RO/DI unit, but when I tried that configuration the waste water wouldn't stop

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.