What's going on here?

vinceM

Good afternoon all.
Can someone explain this set up, please. See pic.

Thank you

Jamie Hall

Looks to me like an elderly steam vent on the drip from the runout to that radiator. Which, if it is functioning properly, well help get steam to the radiator faster. If it isn't functioning properly, it will either be leaking steam all over the place -- which you may not see, but will show up as increased water use -- or the radiator will be slower to heat than it might otherwise be.

vinceM

The rad above heats up nicely, which confused me. With the little knowledge I have, it looks like it's set up incorrectly. It looks backwards. A main vent, T'd off a copper return, below the main?? The horizontal, insulated pipe that says, "library rad", is one of 3 mains. I am surprised to see that a main steam line can be vented from below. Doesn't seem possible....

KC_Jones

As long as it's above the water line in the returns the air can get out. Wouldn't be my first choice, but if it works....

Jamie Hall

vinceM said:

The rad above heats up nicely, which confused me. With the little knowledge I have, it looks like it's set up incorrectly. It looks backwards. A main vent, T'd off a copper return, below the main?? The horizontal, insulated pipe that says, "library rad", is one of 3 mains. I am surprised to see that a main steam line can be vented from below. Doesn't seem possible....

Perhaps it isn't the very best way to vent a main, but it certainly works, and works well, in many applications. As @KC_Jones says, so long as it is above the water line, it's going to happily be venting air, just as if it were above the main. No problem.

After all, the water goes down the pipe, not as a solid stream but in drips and drabs. It won't block the vent in any way.

vinceM

Than you all for the information. Much appreciated.
-On to the next piece of the puzzle....