Knocking banging

marlz827

Good morning. We’re experiencing ongoing issues with one steam line that continues to bang. We excavated and exposed the piping, and the plumbing company corrected the pitch, but the problem is still occurring. It appears to be isolated to a single riser—water begins to discharge from it, and shortly after, the banging starts. Any suggestions or insight would be appreciated.

EBEBRATT-Ed

You have several rads pictured and what looks like a riser in the corner. Which one is banging or is it all of them? Difficult fix in a basement.

marlz827

the first picture radiator is the one that Water starts spitting out and then a few seconds later the next room starts violently banging

marlz827

and the riser that it’s connected to is the only riser in the building banging on the top apartments as well

EBEBRATT-Ed

That pipe has to pitch back counterflow to somewhere it can drain can you show the supply pipe? You can't put steam down under a floor without having a way for water to get out.

There has to be a pit in the floor or a condensate pump or drop to a lower elevation or something. Is the boiler at a lower level? Water has to be able to drain from that pipe somehow. Something is missing.

The other option is to feed steam overhead and convert the old pipe to a return

marlz827

also that first radiator had tons of water in it

Grallert

I would be helpful to see where that supply comes from. There must be a lower level where the boiler lives.

EBEBRATT-Ed

Its steam so the water has to drain (or be pumped ) back to the boiler. If we can't see it we can't help.

Mad Dog_2

Did the floor really need to be chopped up? Mad Dog

Mad Dog_2

Are you the one fixing it or the building owner? Mad Dog

marlz827

Jamie Hall

That whole thing is a nightmare.

I'd need a complete piping plan — elevations and connections — from the boiler to … whatever that arrangement is above… to the convectors. To even figure out what might have been intended to work, never mind figure out what to do about it.

Sorry.

EBEBRATT-Ed

Seems like the Op want's help but without any info we are spinning our wheels. The boiler has to be on a lower level.

109A_5

Where is the boiler ? I'm thinking that floor is about at grade, cars seen through the windows.

Is the system Parallel flow or Counter-flow, I'm thinking the main does not have enough pitch to properly drain the condensate.

PC7060

Last idiot rule says look at most recent change. Agree that boiler height is first place to look. No idea why the floor had to be taken up unless they are replacing pipe.

Mad Dog_2

Likely a Rookie mistake. Need to always think Bypass...let old pipe die on the vine. Mad Dog

kevineggerth

We need elevations and pitches from boiler following thru each listed component all the way to the convectors.

mattblaine13

limited knowledge here. Only know one building: one pipe steam, parallel wet return-gravity return, no condensate pump.

we had bad slope. Fixed it.
no water hammer for one cycle only, so,

Leftover water?

some radiator valves closed but leaks steam into radiator and water ends up in bottom, (eventually leaks back into system)

boiler water carryover each cycle?

Pressure too high on boiler?

after fixing pitch. We discovered a reducer coupling on a return line. Downstream from boiler and right after a riser, looking into that as possible spot water would damn up each cycle

so, maybe you have similar situations?
is that riser elbow in the corner actually higher pitch then where that first support bracket/pipe is?

neilc

the guys upstairs are asking if the boiler is below, under, elevation wise, of the height of the rad and return where you're having problems,

if you manually drain something, the next shot of steam is going to fill it back up as condensate, how is condensate being stopped from getting back to the boiler, it has to go downhill, to get below the water line of the boiler,

can it?