Steam pipe configuration

ari

We are completing a project to upgrade the main venting in a 1920s building. Each basement 3/4" tap previously had a singe Hoffman 45, which the superintendent was instructed to replace with 3 Big Mouth valves. Upon reviewing his work, we came across this different configuration of pipe and can not figure out what it is and if the vents there actually serve any purpose. We were guessing it is some sort of equalization system. Thoughts?

Steamhead

It's a pair of water seals. They keep steam from getting into the return lines by trapping water. The steam can't blow out the seals if you keep the pressure low.

You probably don't need that much venting on them. Move the Big Mouths to the ends of the steam mains before the seals so they'll all have access to the air in the mains. On the seals themselves, a Hoffman #75 or Gorton #1 will probably work fine.

Do those return lines drain into a condensate tank?

ari

No- there is no condensate tank at the building. The end of the main before the seals has 3 Big Mouths as well- seen on the upper left of the picture

Danny Scully

Do you get any banging in that location? The main reduces on the horizontal with a concentric reducer so water most likely pools there.

ari

We do not get banging there, there is a pitch to the left which is not noticeable in the picture.

JohnNY

If 3 vents are good, 9 must be better.

MilanD

You should not be getting any air on top of the "s" shaped seals/pee traps. Vents there do nothing, except - they do look nice Can you take pictures following pipes to the right, and then following the wet return to boiler?

From what's seen in the picture, unless I'm mistaken, 3 vents on the right of the pucture, atop of the inverted "U" are at a top of pipes that should be full of water. Those vents need to go just before wherever the pipes drop to the floor, to the right of what's visible in the pic. They serve no function at that location.

Same on the 6 vents on the left: only the 3 before the pipe drops to the floor (and then goes back up to the next 3) serve the purpose. The other 3 vents atop of the horizontal "S" do not.

Easy way to tell if they do anything is whether you get any air movement at them. Put some seran wrap lightly around the vent. If you get some fogging, you are getting air movement.

You not getting any hammering means pressure is low enough and is not blowing through the traps, so all is well.

gerry gill

Frank is correct that the big mouths were kind of wasted being used on top of the false water pipes. Any vent that can break a syphon would work there.