Lack of dimension A solutions

Cabinfvr1

Looking for suggestions for how to implement a solution to a boiler that has already been installed but is lacking the dimension A height. Add a feed pump? Do I have to trap all returns? What about adding a inverted loop water seal before the pump?

Thanks in advance

Jamie Hall

Can you post photos of the installation so we can see what the problem is?

Cabinfvr1

Sorry, don't have any. I hopefully can describe in more detail. Approximately 1,000,000 BTU, Single pipe steam with multiple dry returns. The boiler was raised on a pad. My dimension A is as low as 10" depending on which return I measure. Water flooding the returns and spitting out vents.

Hap_Hazzard

So, is it just the returns that are too low, or are the mains less than 28" above the water level?

dopey27177

Although this suggestion is costly it will need to be done one time and your problem will go away.

Make all your dry returns wet returns. When that is considered the main vents need to be relocated to the highest point on the dry side of the return.

Te wet returns will need to be 11/4" up to the point where all the dry returns are tied together and enter the boiler thru the Hartford loop. The twined new wet return needs to be 11/2".

Make sure drain Ts and valves are installed on each individual return so the y can be periodically drained and flushed, this includes the section of 11/2" pipe.

The new wet returns can be supported on the basement wall with J hangers.

Based on the information given this the only solution available.

Jake

Jamie Hall

OK. Now. Let's go back to the nomenclature quiz again. You mention "dry return" and you mention "one pipe steam".

Sorry. There are no dry returns on a one pipe steam system. There are often, however, extensions of the steam mains coming back to the boiler. Is that what you are referring to when you use the term "dry return" If it is, Jake's solution above is the way to go. Simply cut off each steam main extension ("dry return") after the last runout. Add an appropriate vent at that location and drop into a wet return.

This, of course, assumes that the steam main at those locations is high enough to suit the pressure (that 28" that @Hap_Hazzard mentioned). If you don't even have that, you almost certainly will have to lower the boiler.

clammy

Just guessing that you have long mains with a boiler that size especially on a one pipe system . I would think that as a one pipe system it was originally gravity return and keeping it that way is always cheaper then adding traps and pumps . Sounds like you need to separate and drop each end of the main drip into a wet return and run back to the boiler .. Large one pipe system w long steam mains usually will have mid line drips that went into wet returns when they are removed and plugged they effect the quality of steam and cause all sorts of issues. If was the case that your system had originally had buried returns that failed and they resorted to dry returns then as advised go back to wet returns . Adding traps and pumps will only complicate something that should be very simple gravity and fairly maintance free . If you can’t get a water seal between each drips height and your boiler water line then adding a false water line and use a vaporstat to run the boiler at lower pressure .of course w a boiler of that size the near boiler piping is quite important .you should have some one who knows what there looking at a take at look any thing is better then traps and pumps for a single pipe Peace and good luck clammy

JStar

You could fabricate a modern equivalent of a vapor return trap using check valves and solenoid valves, but I've never done it in practice before, so the results would be unpredictable. Still, could be interesting!

JUGHNE

Did they move the boiler up from a pit or just up on a 4" pad.
So often the problem is that the new boiler has a water line lower than the old one, but in this case it is now too high?

nicholas bonham-carter

I wonder if a Gifford loop (with its higher connection), instead of the standard Hartford loop would prevent the water from backing out of the boiler into the returns, and flooding the main vents.
Low pressure would still be needed.—NBC

retiredguy

The company I worked for saw very few 1 pipe steam systems since most of what we serviced was larger commercial boilers. However, anytime that I had to replace something on one of those systems, return piping or the boiler itself, I made sure that I documented and took pictures of every water line dimension and any other piping as it related to the boiler so that when the new stuff was installed,the water line dimensions were the same as the original. For the few boilers of this type we installed they sometimes had to be installed in a pit or installed on a raised base. Once you screw up on one of those dimensions, you could not contact the "dead men" to bail you out. my 2 cents

jumper

Reminds me of a trouble shooter who insisted on big bucks in advance to redesign and repipe undocumented screwed up systems. Contract promised any unhappy customer full refund but only after misterTrouble ripped out piping.

retiredguy said:

The company I worked for saw very few 1 pipe steam systems since most of what we serviced was larger commercial boilers. However, anytime that I had to replace something on one of those systems, return piping or the boiler itself, I made sure that I documented and took pictures of every water line dimension and any other piping as it related to the boiler so that when the new stuff was installed,the water line dimensions were the same as the original. For the few boilers of this type we installed they sometimes had to be installed in a pit or installed on a raised base. Once you screw up on one of those dimensions, you could not contact the "dead men" to bail you out. my 2 cents