Do I need some kind of vent or air separator at this return main high point?

newtonkid88

I was planning on capping off the top tee. But should I put some kind of vent up there? Should it be an elbow instead?

The vertical pipe goes back into the boiler.

The two horizontal pipes are from the return sides of caleffi manifolds.

This tee is the highest point in the basement plumbing, other than the hePex risers from the manifolds going up to the HWBB. All the HWBB have bleeder valves.

There is a spirovent microbubbler air remover on the supply side of the boiler, but it is not at a high point.

mattmia2

Any air in that dead end should eventually dissolve and find its way to the air separator. As long as you can purge through it to establish flow it should be fine.

JUGHNE

In places like that I have put in some means to vent the air manually.
An auto vent is always a potential leaker and sometime lets air in.

You may only need it on initial water fill.

Having a lot of misc fittings myself, I have used a male pipe thread X flare fitting with flare cap....easy to loosen and reseals tight.

newtonkid88

Something like this

https://www.lowes.com/pd/B-K-1-2-in-Threaded-Flare-x-MIP-Adapter-Union-Fitting/1000504671

with this cap?

https://www.lowes.com/pd/B-K-1-2-Comp-Cap-LF/5001877617

Does the flare end need any dope or tape to seal?

JUGHNE

Do you have a 1/2 bushing on the top of the tee?

Any size will work, for me it is what ever is handy and often used.
Flare cap fittings need no sealant for this purpose.

newtonkid88

JUGHNE said:

Do you have a 1/2 bushing on the top of the tee? Any size will work, for me it is what ever is handy and often used. Flare cap fittings need no sealant for this purpose.

Yes, i could not find a 1” plug at the time so I used a 1” to 1/2” reducer bushing. Then just plugged that with a 1/2” plug.

mattmia2

You could also just bush it down to 1/8" and put a coin key vent there.

newtonkid88

mattmia2 said:

You could also just bush it down to 1/8" and put a coin key vent there.

I have thought about this. This may be the easiest.

https://www.supplyhouse.com/Ward-FBHE1x1-8-1-x-1-8-Black-Hexagon-Bushing-754000-p

hot_rod

A $2 black plug the size of the tee! You loosen a turn or two until bubbles stop. I suspect it is a one use need if you have piping above that point.