Is this the likely reason for water hammer?

nybigapple

One of the vertical risers in the rear building has bad water hammer, gurgling noises, and you can actually hear echoes of dripping when it's really cold out. When they talk about missloped pipes causing water hammer, how much pipe are they usually referring to? Looking in the cellar this pipe is maybe 4 feet long feeding the vertical riser but perfectly level. Whoever designed the piping did not plan correctly, as the pipe is sitting on a gas line pipe. If the gas line pipe wasn't there, it could hang down and flow freely.

From the elbow it has a nice 45 degree angle into the main.

I find it hard to imagine that much noise could be caused from one somewhat short pipe. I also need to mention, the vertical riser "skips" two floors, before the vertical heat pipe starts. There's a duplex apartment above this, which is a kitchen and bathroom and no heat pipe. From the 2nd and 5th floor there is the long heat pipe with water hammer.

If it is this pipe, how hard would it be to fix something like this. I tried shimming it up from the vertical riser elbow but there is zero give there. I'm not even sure what a repipe would look like.

Fred

In reality, that horizontal pipe looks to be slightly pitched towards the vertical. Yes it can cause hammer and gurggling. Condensation is likely pooling in the horizontal pipe, down towards the vertical and being hit by steam. Noise in a pipe will radiate and be quite noisy. It needs to be fixed to be quieted but you will either have to find another route to get back to that vertical or move the gas pipe. The reason you can't budge it is because it has several radiators attached to it on the upper floors. That's a lot of weight.

Jamie Hall

That sort of looks as though it was piped by the Olympic method -- whichever trade gets there first gets to do it their way.

And yes. You would be surprised how much water hammer a short section of horizontal pipe can create -- particularly when it has a long riser on top of it.

But sorry, I have no clue as to how to fix it!

nybigapple

Yes if you look at the left of the elbow picture you can see that the gas line eventually sits on the waste line too. Just horrible piping.

So there's no obvious way to fix this. Couldn't the 45 degree pipe for the vertical riser be cut shorter, and rethreaded, moving the elbow up and giving the horizontal pipe some pitch?

New England SteamWorks

nybigapple said:

Couldn't the 45 degree pipe for the vertical riser be cut shorter, and rethreaded, moving the elbow up and giving the horizontal pipe some pitch?

That sounds possible. Let's see a pic of the 45, and a wider angle shot with the whole horizontal run-out.

Fred

Is that waste pipe still used? the way it's seriously pitched in both directions, it can't drain properly. If that's the gas line it's sitting on, there may be easier access to take the elbows off of each end of the gas pipe and use two 45's on each end to give you the ability to swing the gas line down a couple inches.

nybigapple

Here's a video of the entire cellar. You can see how much work is needed down there with cracking brick piers under the foundation. But that's another issue. There's certainly room on the 45.

I'd like to call someone in, in the spring to fix this piping correctly. The hammer is worse now after the main pitch was reduced. You can see the black pipe in the end that was placed two days ago from completely rotted pipes. The person who fixed it is not a steam specialist and just does general plumbing. You can see the use of another straight pipe propped by two wood blocks.

That was done because he lacked the proper pipe length, and needed to finish to the turn heat on. He was clearly frustrated as he spent all day fixing this leak due to the tight space. For most of it he was limited to a 14" wrench. I did see him try to use a 24" wrench with a cheater but the pipe refused to budge.

That's what took him so long. He tried using what he could from the old pipes but the new fixtures didn't fit in them. So he slowly cut away more and more of the old piping and sawed out the bushing.

This was definitely a fix the leak at any cost job, and now the main pitch is reduced by the height of those two wood blocks.

http://sendvid.com/ubjlbjij

Just for fun enjoy the pics of how rotted the pipes were.

New England SteamWorks

A little confused:

At :29 seconds in the video we see a tee off of the main. Is this the same take-off that is on the gas pipe and bangs? Because I see no 45 on this take-off.

Or is the take-off with the two wooden blocks the one banging?

nybigapple

Now I'm confused. Maybe I'm using the wrong terminology.

At 0:29 I start focusing on where the main will go to the riser. So it goes up at about a 45 degree angle. A little after it sits on the gas line it reaches an elbow. Then there's a straight pipe maybe 4 feet long. Then another elbow. Then a 45 degree angle pipe which will go into the vertical riser. You can see more clearly at 0:47-0:51.

Couldn't that pipe after the second elbow that goes to the vertical riser be shortened, then the elbow moved up to give pitch?

JohnNY

What's up with that copper section and the part that goes through the sleeve n the wall? None of that inspires confidence. Post a couple pics of the boiler when you get a chance, please.

nybigapple

I was going to eventually ask about that myself as it seemed weird to suddenly reduce the pipe diameter so much. But I thought maybe that was normal for a wet return?

The sleeve is to protect the wet return as it travels across a courtyard back to the front building which holds the boiler. The weird thing is that if you look at the re-entry of the wet return into the front building, the diameter is back to normal. Maybe there was a leak that was previously patched?

I'll post boiler pics a little later today.

Danny Scully

That pipe reduction on the horizontal could be a major source of water hammer, unless I'm misunderstanding the layout. If condensate is flowing towards the reduction, it has no way of escaping the lower portion of the larger diameter pipe. Again, I could be wrong about the layout, but I also don't think it can be considered a "wet" return at that point.

nybigapple

I have been mislabeling it as a wet return. After that last branch, it follows gravity through the courtyard, around the walls of the cellar into the hartford loop back into the boiler. It only goes below the water line right before the hartford loop.

Even as a dry return, there should still be condensate flowing in the pipe through the reduction.

I wonder what the reason for that reduction is. The main doesn't line up to the sleeve without it. Could that have been the reason? Poor piping correction? I mean it doesn't stay reduced as it comes out the other end at 1.5" again.

I've mentioned in another thread how this system loses all its water. quickly. Could it just be this reduction stopping the flow of condensate return?

How difficult would it be to correct that?

New England SteamWorks

nybigapple said:

Couldn't that pipe after the second elbow that goes to the vertical riser be shortened, then the elbow moved up to give pitch?

At :29 that tee would normally have a short nipple and then a 45 afterwards. I now see the 45 at :47-:51. In this case the length of pipe after the 45 going to the vertical riser would have to be shortened, then the 45 reinstalled, and then the pipe before the 45 lengthened to get your pitch. Good luck getting access though to accomplish this.

I am sure you're already realizing it, but you've got a real can of worms on your hands. This is no DIY project. You need one of the pros here like @JohnNY.

And it will be difficult, and it won't be cheap.

nybigapple

RI_SteamWorks said:

And it will be difficult, and it won't be cheap.

That's what it seems like. It seems like the more I look into this, the more problems I find. It's starting to reach a point where things are getting out of hand, and I haven't even covered everything yet.

According to Danny the reduction in pipe could also be a reason for the hammering, and I'm having trouble picturing how that would be fixed.

It's like the only way to solve anything is to solve everything. Which would start with a repipe. But to even repipe the steam lines, you'd have to repipe the gas line and waste lines since they're in the way.

That would be impossible without relocating multiple tenants. To think I only came here last week to figure out how to swap an auto feeder.

Though I am happy it led to me finding the leaking pipe.

New England SteamWorks

nybigapple said:

It's like the only way to solve anything is to solve everything. Which would start with a repipe. But to even repipe the steam lines, you'd have to repipe the gas line and waste lines since they're in the way

A repipe would seem in order, but again, until you have a pro come out and look, things like moving gas lines and tenants are merely speculation.

nybigapple

For the steam experts out there. How easy would it be to fix the horizontal pipe diameter problem? Maybe swap to a slightly larger diameter pipe and install an eccentric reducer?

I'm guessing it's the colder temps and maybe the longer the system runs, but I'm starting to hear knocking in heat pipes further up the chain.

Could a steam professional do it within a day? Any significant risks? Nyc is now getting hit with temperatures in the teens so I cannot risk a long outage.