Supply to return crossover on a two pipe system?

takoateli

We're trying to troubleshoot a two pipe system and wondering if the problem isn't that we have a crossover which is going to equalize pressures.

Any idea

takoateli

Jamie Hall

I don't see the crossover in the picture? A supply main to dry return crossover is a very common arrangement in two pipe steam systems -- however, it MUST include a steam trap, and usually a pair of drips to a wet return (one from the steam main, one from the dry return). Rarely an F&T is used instead. The usual arrangement is piped as follows: straight up from the main, then a 90 and a horizontal nipple to a steam trap (just a regular radiator type steam trap) inlet, then a nipple or pipe straight down from the outlet of the trap to the dry return. How is yours piped?

takoateli

The cross over is running vertical. The blow down for the backflow preventer is strapped to it.

Jamie Hall

takoateli said:

The cross over is running vertical. The blow down for the backflow preventer is strapped to it.

eh? Clearer pictures or maybe a diagram, please?

bburd

What the OP is referring to as a crossover is the equalizer, connecting the header with the boiler return.

Jamie Hall

bburd said:

What the OP is referring to as a crossover is the equalizer, connecting the header with the boiler return.

ah. Well, one does need to have an equalizer...

neilc

Jamie Hall said:

bburd said:

What the OP is referring to as a crossover is the equalizer, connecting the header with the boiler return.

ah. Well, one does need to have an equalizer...

@ethicalpaul

takoateli

Jamie Hall said:

takoateli said:

The cross over is running vertical. The blow down for the backflow preventer is strapped to it.

eh? Clearer pictures or maybe a diagram, please?

takoateli

Thanks guys. Yeah, it's the equalizer.

neilc

I'm not sure you specify what issue you're trying to solve for,

then,
if this last sketch of piping is diagrammatically accurate,
that side outlet "equalizer" is no good, and may be not stopping waters from being thrown up into the system,

can you post a better picture of the piping to and from the boiler, floor to the ceiling,

what issue are you having?

takoateli

neilc said:

I'm not sure you specify what issue you're trying to solve for,

then,
if this last sketch of piping is diagrammatically accurate,
that side outlet "equalizer" is no good, and may be not stopping waters from being thrown up into the system,

can you post a better picture of the piping to and from the boiler, floor to the ceiling,

what issue are you having?

The issue is no heat on the 1st floor.

What's wrong with the equalizer? How should it be?

Now that we found that the dry return is getting pressurized with steam we know where to look.

neilc

Yeah, I see you have the other thread going,
look at any steam boiler install manual and look at how you drew what you have,
boiler risers should feed a horizontal header, then system take offs - take off into the building, then at the end of the header, the header turns down and into the equalizer,
the horizontal header, and proper arrangement of the piping in and out, makes for dry steam,
find those traps that are passing steam

takoateli

neilc said:

Yeah, I see you have the other thread going,
look at any steam boiler install manual and look at how you drew what you have,
boiler risers should feed a horizontal header, then system take offs - take off into the building, then at the end of the header, the header turns down and into the equalizer,
the horizontal header, and proper arrangement of the piping in and out, makes for dry steam,
find those traps that are passing steam

Thanks. Yeah, I did draw that wrong, but if you look at the pictures I think we're good. It's as you describe.

neilc

It wasn't clear if that boiler riser did anything else at the top of the picture,
it just turns down to the drop header and you're good,
you're good, we're good