[mike31154]

I think it's safe to assume your restrictor is in the flush valve, after all, isn't the purpose of the flush valve to bypass the restrictor? Makes sense that it's integrated. Not sure the restrictors in flush valves are easily replaceable though, you might have to replace the whole flush valve unit with one having the appropriately sized restrictor for your new membrane. Otherwise you could simply remove the entire flush valve when the new restrictor you ordered comes in. You could still flush the system from time to time by reinserting the valve assembly, usually pretty painless with the quick disconnect JG fittings. Or just have the restrictor at the very end of your waste line and pop it off to flush. Or a T-fitting with ball valve before the restrictor, there are a number of solutions, as you can see.