circuit setter

Couderay

They are basically the same thing. Look inside same type of set up. Circuit setter being a little more appealing with the built in pointer and ports to check the flows. There are better styles of regulating valves out there but using that circuit setter should be fine.

fatty_2

B&G Circuit Setter

If I were to pipe a small bypass (1") on a small (~50kbtu) hot water system, and use a circuit setter, like the B&G unit i attached a picture of here...
would it function correctly with 4 zones ahead of it? i was worrying, maybe, that the variation in flow through the zone valves would be too much fluctuation for it to truly regulate the return temperature any better than, say a hand bypass (throttled ball valve)
thanks for reading