Okay, okay, you got us, we agree, it does look like a seat. Here’s the difference. A seat has a rubber washer
that actually moves and presses against it, and this shuts off the water. In the Dial-ese application, the end of the cartridge presses against that “stop”
in the valve body, and never moves. Yes, the seal is made using rubber, but once the two meet when the cartridge is installed, they’re never moved
This being said, yes, the stop is removable. In about 1 % of all our repair jobs, excessive water acidity actually ate away the sealing surface of the stop.
(I’ve replaced 2 in seven years) We can order them, but we’ll need to know the length as there are 6 different lengths. Basically, if it ain’t
chipped, don’t fix it!