Water Hammer in 2 out of 4 radiators in a co-op unit. How to fix it?

Fred

If the system is running at 5PSI, you will never fix the system problems or your own, sad to say.

JUGHNE

In your last picture from left to right:
The air vent (not an air valve)....yours is vertical, screwing into a 1/8" hole.
The air vent in mounted in the hole on the high end of the fin tube element, It is a convector fin tube element, though the term convector is usually referred to when speaking of the entire assembly.
The supply steam valve with the handle is the first thing on the vertical riser pipe that comes vertically thru the floor.

The convector element should slope down away from the air vent.....then the outlet when it goes from vertical to the horizontal pipe should slope towards the steam valve.
This would be like a switch back path on a mountain side.
All the water has to drain back down to the vertical riser pipe.

Your steam should come up to your convector, of course as a vapor. When it goes into the fin tube element, your room air being relatively cool picks up heat causing the steam vapor to condense back to a liquid. (The steam shrinks by a factor of 1700 to 1). That condensed steam (water) then flows in the opposite direction by gravity on the bottom of the element and any other piping in the system until it gets back to the boiler.
For your part of the system this is called a counter flow system, the steam traveling in one direction in the upper portion of the pipe and the water flowing along the bottom of the pipe.
So there has to be harmony in the pipe and no head on collisions. High pressure can cause wrecks on that highway. Puddles of water are like a stalled car that has crossed the center line, just laying there waiting for the big guy, (steam truck) to smash into them.

Now if there are any bumps in that path it will collect water and when steam finds that puddle it will hammer.
There has been many comments about the orientation of the steam valve and the way it is mounted, it seems it would collect water in the horizontal portion of the pipe going into it.
There is a "bump in the road" in the part they use for the convector connection. The other part of that valve has a larger opening (with no bumps) that is usually connected to the convector.
If you went to a hardware store and looked at a steam supply valve you could visually see what we are talking about.

As far as high pressure, raising the pressure is a band aid for other problems. It will wreck air vents and slam water around.
Simply lowering pressure has solved many problems.
This has been stated here numerous times.

coophammer

Hi all a quick update - an engineer came by today, and said the issue can be fixed, but I need access through my downstairs neighbor's ceiling, and that going through my floor would be impossible, because the pipes are under the boards, and there is simply not enough room to work on it from top.

Just curious if this rings true with all of you? I think I am stuck without a resolution, because my downstairs neighbor is a lunatic, and hates me for walking on the floor, AND she has painted her ceiling in gold foil, AND she needs to approve any work done on her ceiling.

Jamie Hall

coophammer said:

Hi all a quick update - an engineer came by today, and said the issue can be fixed, but I need access through my downstairs neighbor's ceiling, and that going through my floor would be impossible, because the pipes are under the boards, and there is simply not enough room to work on it from top.

Just curious if this rings true with all of you? I think I am stuck without a resolution, because my downstairs neighbor is a lunatic, and hates me for walking on the floor, AND she has painted her ceiling in gold foil, AND she needs to approve any work done on her ceiling.

He's probably right -- either that or a Sawzall on your floor, which might upset the lady downstairs even more...

Nothing like a coop, eh?

the_donut

I prefer to work from ceiling. However other issues need to be addressed. Turning pressure down below 2 psi cutout would be a good start. Your neighbor will be even more of a lunatic if cutting her ceiling up doesn’t solve the problem.