1-pipe steam main re-pipe

Kjmass1

I have a steam main in my basement that impedes headroom and eventually we’d like to finish off the basement. Is there any technical reason why I couldn’t use 2 quick 90 elbows to vertically raise the pipe +1’ into the joists and do the opposite about 25’ later to bring it back down to the existing level? These connections would be behind dead drywall space but wondering if I should have any concerns with hammering, etc? For the bump up, I’d be able to tie in to the return to allow condensate to drain out...crazy idea?

acwagner

Is this a parallel or counterflow system?

Kjmass1

> @acwagner said:
> Is this a parallel or counterflow system?

Not sure? Single pipe steam with 2 mains and 2 separate returns. How can I tell?

acwagner

Sounds like you have a parallel flow system. The steam and condensate travel in the same direction in the mains.

In a counter flow setup the condensate flows back to the boiler against flow of steam down the main.

Are there any take-offs for radiators on this 25' long stretch?

Kjmass1

> @acwagner said:
> Sounds like you have a parallel flow system. The steam and condensate travel in the same direction in the mains.
>
> In a counter flow setup the condensate flows back to the boiler against flow of steam down the main.
>
> Are there any take-offs for radiators on this 25' long stretch?

No take offs- they’d be after the height adjustment.

Jamie Hall

Technically you can do it. However. Whether counterflow or parallel flow, both the place where it goes up and the place where it comes back down are going to have to have good big drips coming down to a wet return below the boiler water line. Otherwise it's almost guaranteed to hammer like crazy.

Kjmass1

First pic shows where bump up would be after going through beam. Return off to the right there.

Second pic shows where the take offs are towards end of main.

Length is less than 25’, probably closer to 15’.

Kjmass1

> @Jamie Hall said:
> Technically you can do it. However. Whether counterflow or parallel flow, both the place where it goes up and the place where it comes back down are going to have to have good big drips coming down to a wet return below the boiler water line. Otherwise it's almost guaranteed to hammer like crazy.

Added a couple pics. Return is around 5’ high at that point- are you saying that would be an issue?

Jamie Hall

Yup. If the return is above the water line and not separated from the steam main with a trap, it's carrying live steam. It's not really a return, but an extension of the steam main. It might work. I wouldn't want to be responsible for piping it up and trying it, though...

If it's about 5 feet high at that point, not to ask the obvious... isn't it in the way, too?

Kjmass1

> @Jamie Hall said:
> Yup. If the return is above the water line and not separated from the steam main with a trap, it's carrying live steam. It's not really a return, but an extension of the steam main. It might work. I wouldn't want to be responsible for piping it up and trying it, though...
>
> If it's about 5 feet high at that point, not to ask the obvious... isn't it in the way, too?

I’d like the return to be re-piped flush to the foundation as well- height I’m not too concerned with.

What if where the bump up was, it had it’s own dedicated condensate return- dropped straight down close to the floor and then tied back in to the main return at the boiler/water line?

Appreciate the info- sounds like it would be a tough sell for a steam guy to take on, which is unfortunate.

Steamhead

@Kjmass1 , am I right that you're in Massachusetts? If so, there are plenty of steam guys there who you could get to look at this- try the Find a Contractor page of this site.

acwagner

In the one photo that shows the main going through the beam, does the pipe keep going straight through that wall behind it to the boiler?

Any chance you can raise the main all the way from the boiler to this section of pipe you want adjust? That might allow you to raise the main out of the way and avoid doing the double 90 offset.

Kjmass1

> @acwagner said:
> In the one photo that shows the main going through the beam, does the pipe keep going straight through that wall behind it to the boiler?
>
> Any chance you can raise the main all the way from the boiler to this section of pipe you want adjust? That might allow you to raise the main out of the way and avoid doing the double 90 offset.

In theory there is enough room to go up and over the 2 carrying beams through the joists- there are 2 risers so that might be tight. There is a 90 back to the boiler so at that point you perpendicular to the joists so I don’t think that would be possible.

mikeg2015

I repaired a pipe on a moline system that had one main that ran lower than the rest. It had a drip to send condensate back to the end of the main (dry return). However, the system has to run under 1psi or steam will push the condensate out of the 6’ long drip.

Shocker.... it was set to 5psi, 3 psi diff. So it had live steam most of hte time and probably hammered and heated like crap. Was also a Bryant (Dunkirk) and header has minimal A dimension and was small for hte likely oversized boiler. Of course its been converted to 3 apartments, half of which is already forced air. I’m sure I’ll be there some time this fall when it quits working.