Webster Vent Trap??

Paul S_3

Hey guys. Hope all is well. A friend of mine is on a job and he is asking me if I know what this is. is this just an air eliminator or a vent trap. Steam is leaking out the top. It doesn’t look like a boiler return trap. Also what can be done to replace this because it’s not a threaded port on top.

Steamhead

It's a vent trap which is the same as air eliminator. Not sure what brand.

He needs to look for the bad trap that's letting steam into the dry returns that the vent trap is connected to. Just follow the steam-hot return to whichever rad return runout(s) are steam-hot.

Paul S_3

thanks @Steamhead so it has to be a bad trap or traps at the radiators. Even If the boiler pressure got too high from a clogged pigtail and backed water up into that vent trap the vent trap float would close the vent and air lock the system? Is that how these work?

Jamie Hall

More or less. The key is the comment "steam is leaking out the top". On two pipe steam systems, steam should neveer get into the returns (well, hardly ever — but that's another matter). If it does, some steam trap somewhere has failed — and you need to find it.

The float should close the trap outlet if the pressure gets too high — but there are a host of other problems high pressure will cause, most of them non-obivious, so get the pressure under control as well.

Paul S_3

can this be replaced with a return venting manifold as long that the boiler pressure is maintained low ?