What kind of check valve to use?

[velvetfoot]

I want to prevent ghost flow, and want to put the valve in a horizontal section.

Thanks.

 

[R Mannino]

Weighted flow checks are commonly used.

http://flopro.taco-hvac.com/product...e_and_flow_control_valves/flo_chek/index.html

 

[velvetfoot]

I have those in 3/4" on my zone inputs. I'm thinking of putting a 1.25" check on the supply header. It would be at the same level as the top of the tank, more or less. The flow I'm thinking of stopping goes from the top of the tank, through the recirc line, and back to the bottom of the tank. I have to look at how the thermostatic boiler protection valve works, but a fair amount of the pipe insulation is off now, and I can feel what's going on. It's good insulation though, 1" foam, so I hope it's worth the added flow restriction.

 

[maple1]

I have a couple checks in my system. I just used the ordinary (unweighted) [cheap] flow checks. Have one 1" & one 1-1/4". Don't think they're recommended as the best solution, think a primary complaint was chatter. But I have never heard chatter from mine. Their main focus isn't ghost flow but pumped flow (at low flows), with me.

I took the flapper out of the 1-1/4" one this summer & drilled a 1/4" hole in it to let some flow from storage into the circuit when my backup electric boiler was running, to help reduce short cycling. That does cause me to heat a bit of my storage water with my electric boiler when running backup, which I originally didn't want, but it's not much. Turned out to work pretty good. Was nice to be able to do that, helped tune one aspect of my system in after the fact.

 

[velvetfoot]

At this point, I'm of the mindset of getting things together and not messing with it for awhile.