That might work.boyntonstu wrote:A quick and dirty solution would be a PVC 'T' , a length of PVC, a cap with a hole in it, and a rubber tire Schrader valve pressed through it. (or copper)
I have tested pressed in Schrader valves to 600 psi.
And not so unlike building a spudgun.

-IF- this works, then a foot of 2" pipe for the chamber, would probably handle just about any problem.
And you are absolutely correct. All expansion chambers were simply a chamber of whatever size, (usually a zinc coated tank about the size of a water heater.), with a schraeder valve... Up until the advent of those with a bladder.
We would have to periodically "top-up" the air. To do so meant emptying the tank, first.
I think, though, that there is a bit more to the anti-water-hammer units, like the one I linked to, than just a chamber with air in it.
If the plumbing is going to be open to put the sprinkler valve in it, anyway, it would be almost no extra trouble, to put one or two of those ten dollar A-W-H units in there, after the sprinkler valve...
And those units are built specifically to handle water hammer. -Without- periodic attention...