Veco system brought back to life

jstephanou

I recently moved into a new to me house, with a 1940 Veco 2 pipe steam system. It has recessed convectors in the walls. Has inlet one-turn throttling valves and thermostatic Bellows type steam traps. Also has dry return but also has a wet return similar to the one shown in the lost Art of steam heating on page 436. 

I noticed over the last two winters that are steam heating gas bills were through the roof the boiler was replaced probably 10 years ago with a Weil McLain boiler. I noticed that the pressure would cut out at four and cutting it two. Way too high. Upon investigation I could not find any vents anywhere on the dry returns or frankly anywhere in the whole system. Apparently when they replaced the boiler they must’ve piped it incorrectly and removed important items. After reading and learning I cut in two  Hoffman 75 vents high up  in the dry  returns in the basement and the system heats up incredibly fast. Thanks- Lost art of steam heating. I also added a vapor stat and now control the boiler up to about 14 ounces of steam pressure. I kept the pressure control as a back up and wired them in series. Any further advice to improve the system is appreciated. Also, I had to replace some of the trap internals as they were  actually missing entirely as they were removed. I also rebuilt some of the inlet valves as the washers are long gone.  I put in some cage units from Barnes and Jones.. people really screwed up this system. It works great now. Any thoughts on further improvements? 

PS – the other part of the story is during the previous house renovations, two convectors and subsequent valves and traps were taken out of the system and discarded. People have no clue!

neilc

keep the water clean,
skim port ?
return flush ports ?

Steamhead

jstephanou said:

Any thoughts on further improvements?

Vents at the ends of the steam mains?

jstephanou said:

PS – the other part of the story is during the previous house renovations, two convectors and subsequent valves and traps were taken out of the system and discarded. People have no clue!

Yeah, you can't fix stupid! Fortunately, convectors and their associated hardware are still available.

jstephanou

Yes there are flush points at the wet return, but i had to install them!  The skim port plugged with a large plug. Need to get some type of big socket to unscrew. 

Also, for venting The end of the steam main, I was wondering about that. If you look at the picture showing the steam pipe with the drip, it shows a wet return line dropping down to the ground and running back to the boiler. I assume therefore the steam would go pretty dry and not be much of a problem? I also read that for these two pipe systems, you  would typically vent through the steam trap and back to the dry return as I did. Do you all think that I should install a vent at the end of the steam main in that pic? Thanks for the help.

EBEBRATT-Ed

Venting the mains may speed up the heat. But you be the judge. When the boiler header gets hot how long for the steam to get to the end of the mains? With all the traps open if you mains are not too long you may not need vents

Steamhead

Later Trane Vapor systems had vents at the ends of the steam mains, as well as on the dry returns. There's no reason your VECO can't use them. How long are your steam mains, and what pipe size?

jstephanou

Thanks for the comments. The steam main in the basement is a 15’ x 45’ rectangle , so about 120 feet total  of 2.5” pipe. The boiler sits at the one end of the 15’ sides, and the mains are sloped and drips to the wet return to one corner on the opposite 15’ side, as shown in the pic further below. I have not timed the steam to reach that far corner, but will check. 

Also, with the 1 1/2” tap for skimming, is it common to have a permanent take off to skim, or just skim during annual maintenance?? 

Thanks 

jstephanou

see pic of wet return drip off of steam main mention in above. 

Danny Scully

Veco systems typically had the dry return venting into the chimney. We came across one such system that still had this arrangement. Our approach was to most closely match the venting capacity of 1-1/4” pipe. This is what we came up with. 

jstephanou

Danny Scully said:

Veco systems typically had the dry return venting into the chimney. We came across one such system that still had this arrangement. Our approach was to most closely match the venting capacity of 1-1/4” pipe. This is what we came up with. 

jstephanou

Thanks for that info. I read about that in an article on these Veco systems. As I mentioned, I suspect my system was totally screwed up when the previous owner removed the boiler and NO vents put back. So right now, I have 2 dry returns (1 1/4 ) coming from two different parts of the house. After  the last condensate return in each leg and before the drop to wet returns, I added a Hoffman 75 (so two total). Are you saying that should consider more vents to make up the equivalent of the 1 1/4 previous vent? Thanks again. 

Ps - I am not a contractor, just DIY person that likes to fix problems!