Vapor Steam Boiler -- What is this? How to replace?

Replacement

I need to replace a steam boiler that is original to my "new" 1928 home (massive boiler converted from coal to oil to gas). I have been receiving estimates for the job and the consensus seems to be the boiler will need to be ~450,000 BTU.  However, I cant get consensus on  what type of two pipe steam system I have.  Here are the facts:  Top of boiler has a gauge for pressure/vacuum, there is a Bromwell #1 box hanging off the front of the boiler and there is a huge vapor tank (unless the vapor tank is the bromwell unit and the huge tank off the bakn is just a hot water contraption).  I have two very strong quotes: 

First Quote:  boiler piping with cast iron fittings from new boiler to existing

system main piping and condensate return piping in “drop-header” configuration as per local codes and manufacturers’ instructions and piping schematics. New near-boiler piping to be configured for very low pressure steam. Existing suspended vapor tank and trap to be eliminated.

Second Quote:  Will replace boiler and configure for existing vapor system.  pricing includes condensate pump, and all necessary F & T traps at ends of new mains.

Are these two solutions equal but different ways to solve for low pressure steam or "vapor" system?  Do I need a condensate pump?  What is drop header and why is only one guy recommending?  Why?  Any guidance on who I should trust or what I should be asking would be greatly appreciated!!!!  Seems vapor systems are rare in homes and only 2 of 7 plumbers have indicated this isnt a "normal" two pipe steam system (note all plumbers are mid-sized outfits....).  Please HELP!

lchmb

first

How about some pic's of the close boiler piping and connected tanks and lines and some pic's of the radiators..Include views around the boiler..

Tim_Hodgson

2 pipe vapor

Your system is probably a Broomel vapor system. Most likely the new boiler holds 1/2 the water volume of the existing boiler. You will probably need a "boiler feed" pump not a condensate pump. I believe the drop header is what we call a "False water line" to maintain a wet return water seal. You will need this so you do not have to install traps on each radiator. The keys to making this system work are: Do not exceed 1 pound of steam pressure, Lots of venting if you remove the ceiling vent radiator, no pressure in the condensate line.  Basically, make the new boiler adapt to the existing piping.

The first bid sounds like he understands the system better.

Good Luck,

Tim

Steamhead

Hold off on the boiler-feed or condensate pump

Most times the new boiler really does have enough water content. Adding a pump requires extra traps out in the system, so there is much more mechanical complexity. We have removed several of these unnecessary units.



With the pressure low and the proper vents, the steam will be in a more expanded state which will fill more space in the system.



If you're skittish, order your boiler with one extra section and down-fire it to match the load. This will give you some extra water content.



Finally, the Broomell System is covered in chapter 15 of "The Lost Art of Steam Heating".  Order your copy on the online store of this site.



And post some pics!

moneypitfeeder

not quite

A drop header is installed mainly for convenience, it allows you to bring your risers the full height the manufacturer recommends, and then drop to a height as low as the top of the boiler to give the fitter more room to make their take offs to the main(s) and connection to the equalizer without being in the rafters. I would recommend the header either dropped or not, be oversized to allow for all the water to collect and drain to the equalizer, and still provide space above the water for the steam to exit to the mains.  But I'm just a homeowner, take it with a grain of salt.

Replacement

PICTURES!!!!

Thank you everyone for the guidance.  Perhaps these pictures will help.

Replacement

PICTURES!!!!

Thank you everyone for the guidance.  Perhaps these pictures will help.

Charlie from wmass

Am I missing something here?

450kbtu for a replacement? How are they sizing the new boiler? Pumps are best for forced hot water systems and industrial high pressure boilers. Most residential boilers I came across do just fine without extra doodads added on. Keep it simple and it will keep you happy.

Replacement

sizing

21 radiators + garage has a 53 blade radiator.  5800 sq feet of heated living space.  I think they approximated 1.1 or 1.3 x the sq footage of the radiators to incorporate the long runs -- the house is very long/spread out and only two stories.

Charlie from wmass

Where are you located?

some times even medium size companies are too big. The person looking at the job seldom sees the job after it starts.

clammy

broomwell ?

I used to see alot of broomwells years ago and it looks like maybe your rads have had some work done on them ,most of the broomwells i have ran into have had only traps ells on the returns and graduated (orifice type ) hand valves.When ever i have seen regular traps on these systems it is usually because they where converted from coal to what ever  a standard pressuretrol was installed depending upon where they installed the thermostat determined wheather or not they had issues or not .I say this because i have seen some broomwell work fine with a standard pressurtroll because of  the t/stat location while i have also seen it work the opposite way where the system would build pressure 1 .5 psi and all sorts of promblems start to occur like steam in the returnsand no steam distrubtion and inlet hand valves leaking so usually a guy comes sells new hand valves and traps and all seems well no more steam leaking and no more steam in the returns but at the cost of higher fuel use and terrible steam distrubition.I also am a firm believer in no condenstate pumps on systems that have never had them ,Install a over sized drop header ,a false water line to copy the original boilers water  and install a vaporstat and run the system at no more then 8 oz .It may be very wise to look at light commerical  wet base boiler that uses a gas gun that has a hi fire low fire options they usually always run a little more eff then a dry base atspohertic gas fired boiler and some times have a larger water content .Also make sure who ever replaces your boiler takes a good look at your systems piping and see if you have a functioning crossover traps alot of larger brommwell and vapor systems will have them out there some place.Make sure your returns are clear and get them flushed out and last but not least make sure a secondary electronic manual reset low water cut off is installed and if  a automatic watre feeder is installed make sure it is a hydrolevel svt unit which will record how much water has been added to your system.Make sure the company who replaces your system has this all ironed out before they start other wise there shall be issued.Don't want to sound negative ,broomwell and most vapor system operate excellent and where the rolls royce of heating systems back in the day and when maintaned and operating properly they are amazingly quite and econically to operate .Peace and good luck clammy

Jamie Hall

Those Broomell systems were wonderful...

And there's no reason why they can't be wonderful in the 21st century.



A few thoughts (besides Clammy and Charlie and Steamhead, who really do know their business!)



First, if you get you installer to set the new boiler so that its water line is within an inch or two either way -- that is up or down -- of the old boiler, you won't need a false water line -- or if you do to keep something working, it's because something got messed up somewhere else in the system.  So keep the water line in the new boiler where it was in the old one.  This may mean setting the new boiler up on blocks, but that's OK -- just make it solid.



Second,, a drop header is there to make drier steam.  It does, sometimes, make hookiing up to the rest of the system easier.  Sometimes not.  But it will make drier steam, and is recommended (highly).



Third, Clammy noted crossover traps.  How right he is.  They go from a steam main to a dry return, and allow air out of the system.  If they are stuck shut, the system will heat unevenly and slowly.  If they are stuck open, the system may not heat at all.  But if they are working, they're great.  If you have them, you will also have one or more main vents where the dry return(s) drop down to the boiler.



You don't need any pumps nor condensate tanks nor fancy whizbangs and doo-dads like that.  All they do is cost money and fail.  That is, you don't if the returns aren't clogged.  If the returns are clogged, it is easier and cheaper to flush them (or replace them, if they are leaky!).  Yes the water level will drop when the system is firing.  No it shouldn't drop far enough to be a problem.



Do check your required boiler size -- the figure you quote is a pretty dang big boiler for a residence.

Jamie Hall

Those Broomell systems were wonderful...

And there's no reason why they can't be wonderful in the 21st century.



A few thoughts (besides Clammy and Charlie and Steamhead, who really do know their business!)



First, if you get you installer to set the new boiler so that its water line is within an inch or two either way -- that is up or down -- of the old boiler, you won't need a false water line -- or if you do to keep something working, it's because something got messed up somewhere else in the system.  So keep the water line in the new boiler where it was in the old one.  This may mean setting the new boiler up on blocks, but that's OK -- just make it solid.



Second,, a drop header is there to make drier steam.  It does, sometimes, make hookiing up to the rest of the system easier.  Sometimes not.  But it will make drier steam, and is recommended (highly).



Third, Clammy noted crossover traps.  How right he is.  They go from a steam main to a dry return, and allow air out of the system.  If they are stuck shut, the system will heat unevenly and slowly.  If they are stuck open, the system may not heat at all.  But if they are working, they're great.  If you have them, you will also have one or more main vents where the dry return(s) drop down to the boiler.



You don't need any pumps nor condensate tanks nor fancy whizbangs and doo-dads like that.  All they do is cost money and fail.  That is, you don't if the returns aren't clogged.  If the returns are clogged, it is easier and cheaper to flush them (or replace them, if they are leaky!).  Yes the water level will drop when the system is firing.  No it shouldn't drop far enough to be a problem.



Do check your required boiler size -- the figure you quote is a pretty dang big boiler for a residence.