Sand (rust) storm inside mains?

JShep

After employing a car Jack and a 4x4 post with a curve notched out of one end to better spread the weight out, I managed to rectify a 4” down slope at the end of a 2.5” 20’ long main that feeds the entire back of the house (5 floors), buying back about 1.5” of upward slope… eliminating whole house shaking hammer.

When steam heads up the riser at the end of this main now, we had at first what sounded like freezing rain on a car roof and after a few cycles turned into what sounds a bit more like a sandstorm hitting the inside of metal pipes.  It’s not hammer… it’s a consistent sound for the first several minutes of a cycle, no shaking of the pipes, no surging.  If it weren’t for knowing it shouldn’t be doing that, the sound is actually kind of relaxing.

As the main was holding residual condensate for likely a decade (piecing together notes from the prior owner), I’m guessing a decent amount of sediment and rust flakes settled in the negative sloped section of pipe and now that it’s dry it’s getting carried along through the rest of the system by steam as it passes.

So… now what?  I’ve got a rad about 12-14’ straight up on the second floor that I need to swap the 1/2” line feeding the valve (I’ve got a very mild leak around the threads between the pipe and valve and the line is too short to achieve the right slope to properly drain toward the trap).  I could easily achieve a temporary… turbo vent… out of the back of the house by swapping the valve with a 90 and putting a section of pipe out a window.  Alternatively, I could run a hose to the line that feeds the radiator and flush water back towards the boiler, but then I feel like I’m feeding a bunch of crap to the three crossover traps along the way and either back into the boiler or a significant amount of buckets I’d have to haul in and out throughout the process if I disconnect the risers from the boiler so I can catch it before it makes it all the way back.  The latter plan seems like more work and more potential for clogging up other stuff along the way.

so barring any other ideas on how this traditionally would be tackled… looks like I’m dumping a bunch of sediment filled steam out the back of the house this weekend.  Maybe I can two birds one stone the situation and hot sand blast the paint off some old traps and valves I need to rebuild by clamping them in front of the outlet?

Jamie Hall

Are there drips to a wet return near the crossover traps? If so, if you were to figure out how to run water into the mains it would go down the drops (if you weren't over enthusiastic) and thence to the wet returns, and then if you could flush them out...

Otherwise. Hmm. I love the idea of a turbovent! Whoosh! Just might work, too.

Waher

Add a steam rated wye strainer somewhere and empty it regularly?