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

Works like a wonder, and at this price for 2 is unbeatable + I used it at "Reliance Osmosis."

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.

I replaced a "whistling" shut off valve with this one. It is working great.

Bought this to replace my original auto shut off and it workes great so far. It has been over a year now. I will be buying again when i need one.

if your RO faucet starts to output a weaker stream and you are sure your storage tank empty pressure is correct then this is most likely the problem and its really easy to install; just move one tube at a time and you will have no issues.