Replacing a sink isolation valve
 

Has anyone replaced one of their sink isolation valves (the ones that "pop" open & closed)? Are they soldered/sweated in, screwed in, other? TIA!!

There are lots of YouTube videos on how to replace the Accor plastic push-pull valves. Basically, they can be removed by just turning the valve in a counterclockwise direction. Note that the Accor valves have a 10 year parts and labor warranty, but most people prefer to use a different type of replacement valve.

One of the easiest replacement solutions is to buy a Sharkbite valve that is already attached to a sink supply line. You just remove the Accor valve and attach the Sharkbite valve to the pipe stub, and attach the supply line to the sink faucet connection.

All of the pop off valves I have seen are plastic (PVC I think), if you go to ACE hardware (Wildwood) there was a gentleman there who explained in detail how to do this with the sharkgrip replacement valves. I have not done this yet as I was actually looking for replacements for a slightly different installation.
What I was told, was the existing pop off valves are a twist off type design.
Be sure you turn off your main valve (in the garage), and open both cold and hot water valves to relieve pressure in the system before you start to work on your valve replacement. One of the neighbors had this done, and as I recall the plumber charged over $50 valve. If you are not comfortable doing this yourself, call around and get estimates before you hire a plumber.

Those pop-out valves are a safety feature that will pop if the pressure in the system gets too high and the expansion tank relief valve fails which they do especially if you don't test them very often.

I’ve had this happen when the pop-up valve engaged before the expansion take the safety valve. The expansion tank has waterlogged no room for expansion.

Note that the Accor valves may close with high pressure, but that is not a design safety feature of the valves. According to Accor, their push-pull valves should not close under high pressure.

Thanks very much for the replies. They were very helpful. Most important was finding out the equipment brand name, Accor. Yes I found out that you can remove the Accor valves by turning them counterclockwise and pulling on them. I am probably going to get a plumber to do this for me; as noted in one of the posts I don't really feel comfortable doing this work.

Viagra wasn't supposed to be an ED feature but it is.

The point is maybe it wasn't designed to work as a safety feature but it saved my butt when my safety relief valve on the tank obviously failed.

It's a closed system so why would Accor think it wouldn’t pop out under high pressure?????

I don't disagree, but some people think that the Accor valves are designed to pop closed at a specific pressure.

For those who want to check their water pressure, buy a 10 dollar pressure gauge from Amazon that will screw onto an outside hose bibb. A good pressure is about 60 psi. The pressure relief valve on the water heater is designed to open when the pressure exceeds 150 psi. The problem is that is too high, and the valve may open and only release about half cup of water and then close. So, you don't even know that it tripped.