Iron fireman/ mini tube steam system

Kaziak

I am currently working on an above described system and my boss wants to remove the condensate tank and pumped return. Everything I find says this is wrong and is needed for proper operation along with steam and f&t traps, all of whom are already on site. How to properly replace boiler and common mistakes would be appreciated. Thanks in advance. 

Steamhead

Unless you have a "B" dimension of 13 feet, you need the pump. This is one exception to our usual rule of not using condensate pumps on gravity-return systems. The SelecTemp system uses higher pressures so the "B" dimension is much greater than usual.

Manual is attached. @Erin Holohan Haskell might you want to add this to the SelecTemp page of the Museum?

Mad Dog_2

You Da man, Steamer!  Mad Dog 🐕 

retiredguy

I had some experience with one of these systems about 25 years ago. It was in a church and attached 3 story meeting hall. At that time the heating system ran very well but the boiler needed to be replaced. The church pastor and maintenance team all stated that even though the system ran well, replacement parts for the heating units were almost non-existent. Most of the replacement parts and especially the steam coils were being hand made by a third party at a very high cost. They realized that at some future time that they would have to replace the system. The entire system was replaced about 5 years later using Slant Fin wall convectors.

This system had many great advantages such as a self contained modulating thermostat which would control the heat to the space with good accuracy by controlling the steam supply to the coil and at the same time vary the speed of the blower fan. Also the heating units did not have steam traps but instead used a capillary tube to allow the removal of the condensate. The only traps that I can remember were at the end of the steam mains. This system worked well until it didn't.

EBEBRATT-Ed

@retiredguy I agree I only worked on one system also in a church in Hartford, CT. The little blower fans were not turning in some units. We cleaned them up and oiled them up and got them running at least for the time being.

@Kaziak that system will not work if you monkey with it too much. They do run higher pressure as @steamhead mentioned. It is unlikely that you have enough height to return the condensate without the pumps

Kaziak

EBEBRATT-Ed said:

@retiredguy I agree I only worked on one system also in a church in Hartford, CT. The little blower fans were not turning in some units. We cleaned them up and oiled them up and got them running at least for the time being. @Kaziak that system will not work if you monkey with it too much. They do run higher pressure as @steamhead mentioned. It is unlikely that you have enough height to return the condensate without the pumps

I agree everything said here, the unfortunate part is this system was already monkeyied with and we are the poor souls trying to resurrect it. Everything so far has been gold keep it coming if it exists I'm a nerd. 

EBEBRATT-Ed

@Kaziak

I would just follow the manual @Steamhead posted. Those systems differed from the typical system so they can be easily screwed up. Not that there are many left that know how the typical systems work.

retiredguy

The system I mentioned utilized a steam pressure of 10 PSI. The modulating thermostat controlled the steam to a steam nozzle which would power the turbine fan which in turn, powered the air producing fan . The speed of the fan was dependent upon the amount of steam the thermostat allowed to pass. The exhaust steam went to the coil to provide the heat. The capillary tube allowed the condensate to escape the unit and went to the condensate return to the condensate tank. Looking at the overall engineering of the system it was a great idea and if installed correctly everything worked well as long as the boiler produced dry steam. Wet steam to the heating units was a problem. Water carry over was a problem. Service guys that don't have a clue are a big problem. When or if you get this system working well, "let it alone". Don't try to make it work better. And, tell your boss that the condensate tank must stay. If you need help with the replacement of the boiler I would list the address and see if any of the guys that monitor this site are available to do the work or be a consultant. The guys on this site are well versed on steam systems and on how they should be installed.

EBEBRATT-Ed

Usually these systems utilized an Iron Fireman pachaged steel boiler

Kaziak

So as a follow up we replaced the tank, removed about 20 air vents, and returned the system to the original design as much as possible, the units where retrofitted with becon Morris kick space heaters. System is capable of having heat at all units with <2psi steam. We have yet to install a meter on the tank feed or see if it wants more pressure under load. Let me know what to look out for from this point plz. Also thank you for the comments links and help

EBEBRATT-Ed

Since you don't need steam pressure to run the fans I guess lowering the pressure is fine. You will find out when the weather turns cold.

tim smith

Frank, great find on the manual.

ChrisJ

Steamhead said:

Unless you have a "B" dimension of 13 feet, you need the pump. This is one exception to our usual rule of not using condensate pumps on gravity-return systems. The SelecTemp system uses higher pressures so the "B" dimension is much greater than usual.

Manual is attached. @Erin Holohan Haskell might you want to add this to the SelecTemp page of the Museum?

I just want to point out something I believe Gerry Gill mentioned many times.

As per that manual, and I don't think they're wrong when it's used correctly :

Steam supply mains may be run with either iron or type L copper pipe. The copper pipe with soldered joints will be found more economical in sizes up to two inches. Iron pipe will generally be lower in Cost on mains larger than two inches or those in which few or no tubing take -offs are made.


By correctly, I mean copper pipe needs to be laid out in a fashion that allows expansion and contraction, it can't be jammed between two risers on a cast iron block with absolutely no way to flex. It also needs solder joints that are decent, not someone straining to use an undersized torch to try and solder 2" or 3" pipe that has never done it before.