B&G balance valve to throttle Termovar?

[Highroad281]

So I bought a 3/4" B&G circuit setter a while back intending to use it for something else, but now that I'm closing in on the install of my Solo40 I'm trying to find a way to work the valve into the build.

I think it was Bob R that I read recently that stated ball valves make terrible balance valves, and that got me thinking. The Tarm install diags show using a 1.25" ball valve closed 50% between the boiler supply and the Termovar to presumably keep the thermostat from allowing too much flow when not needed. Ball valves are certainly cheaper than the balance valve, but since I already have it I'm hoping to make use of it.

Question: Seems to me that the 3/4" balance valve wide open should provide basically the same flow as a half-cracked 1.25" ball valve, right?

Also, are there any circumstances where I might need the full port 1.25" valve that I'm not considering?

Not sure it matters but the circ is an 007, all other near boiler piping is iron 1.25", and the integrated shutoff ports on the Termovar don't really seem any bigger than the port in the balance valve looking at them side by side.

 

[Highroad281]

Figured I would reply and put this to bed. This idea officially filed under category "maybe you could, but dont".

I ended up not using the B&G , and I'm glad that I stuck with the full port 1-1/4" ball valve for a couple of reasons.

First off, I switched the 007 to an Alpha. The CP2 mode is just about perfectly matched to the Termovar with the ball valve wide open. Glad I'm not dealing with another restriction that the B&G would have imposed.

Secondly, having that ball valve where it was was a huge help when trying to purge air during startup. I'm not done with the air yet, but getting better by the hour for sure.

Anyway, can't state enough how thankful I am for all the details, info, and advice that I was able to find in this forum. As for my bright ideas, when in doubt- follow the directions!