T&S Brass 016419-25 3/8-Inch Compression Check Valve Assembly

These are used in commercial restaurants and when a so called plumber installs a faucet without these you will have cross over. Must have to prevent cross over.

After installing a faucet with a pre-rinse sprayer in our kitchen, I noticed if the mixer lever wasn't immediately turned off after use that hot water was entering our cold water line and vice versa (depending on which line had more pressure) to the point that even in our bathroom we were sometimes getting hot water from our cold water line and vice versa. Looked everywhere for 3/8" comp male-female check valves for water use and not easy to find. Plenty of low-grade 1/2" options out there that I could have installed with reducers, but didn't like the idea of poor quality check valves plus having to convert thread sizes. These were the only option I found but seem to be of very high quality rated for commercial use and manufacturer's website states they're made in the USA, which gives me a little extra confidence in them. Mini mesh strainer included to help them hold up longer. Just installed today, but already seems to be doing the trick as the cold supply line remains feeling cold to the touch and hot supply line remains feeling warm to the touch. Thank you T&S for making these. Worth every penny.

This small compact screen check valve is ideal and very hard to find. Easily installation,Installed in minutes . Perfect fit and works as purposed.

Works great for no mixing on hot/cold bidet…on both hot and cold.

Did not fix our issue with resetting the device!