In this area, there were many newer tract homes built with a novel type of push/pull shut off valve with all-plastic construction. Most of these are made by a company called Accor Technologies.
These are push-to-connect valves, which means that they are installed without any tools. An O-ring is what seals the valve to the pipe, and stainless steel grip rings are what hold the valve onto the pipe. In these ways, they are very similar to other push-to-connect fittings like those made by SharkBite.
Unlike SharkBite fittings, however, they are cheaper to purchase in bulk due to the all-plastic construction. They either have plastic ⅜” threads for connecting traditional supply lines, or they have integrated supply lines that cannot be replaced.
They also turn on and off in a unique manner. Instead of rotating a knob or lever, they have a round push/pull knob. The knob is pulled out to shut the water off and it is pushed in to turn the water back on. This is a very short movement, and the handle pops into place when it is either on or off.
Because of the novel mechanism, these valves can sometimes turn off on their own if there is high water pressure or water hammer present. They can also leak from the seam where the integral supply line connects or from the connection point to the pipe. We recommend replacing these valves when changing out the faucet.