Clogged Main Steam Vent?

TheClevelandSteamer

Here's a Hoffman 75 main steam vent installed on my system. There are rust stains on the vent body and the 7" nipple below it. It's at the end of the return line, behind a swing check valve and a large trap.

Does this give the appearance of a clogged vent?

dabrakeman

What does it do during a heat cycle? If it were fully stuck shut it would not get steam hot, maybe somewhat hot from conduction through the pipe. Track the steam to it. Also want to make sure it closes on steam even if it is not stuck shut. The rust path indicates to me that it at one time either failed open or there ewas a lot of carryover water from the boiler getting into the system. You can take it off and blow through the bottom to verify if it is open. This will not tell you if it closes on steam though.

mattmia2

it is ancient and tiny but the only way to tell if it is clogged would be to remove it and try to blow through it.

ethicalpaul

Well you can feel if it is passing air, or hold a piece of toilet paper over it to see air blowing it, no?

dabrakeman

https://forum.heatinghelp.com/discussion/comment/1889916#Comment_1889916

Permanently 😄