Cadillac Tower 40 stories of fun!

David Minuz

This is a two pipe system on a 40 story building built in 1929.
Along every support column on the outer wall is a supply and return serving two radiators per floor from 3 up to 40.
I was there to fix a heat pump on 2 when the maint guy asked me to help with a wave of no heats coming in near the end of my day. His radio kept crackling and his eyes just rolled as every floor from 21 to 37 were calling his office. All were located on the same steam line.
He said he had this problem last year, he bleed the line up on 40 and cranked up the pressure and the problem went away. This year he has the pressure up to 6 psi.! :) oh boy
On floors 40 and 39 he had the supply pipe open. We found the a lazy trail of steam coming out when we went and attached it back up. The radiator did warm up.
Down on 21 the start of the problem I opened up the return at the steam trap and noticed a jet of air, perhaps about 6 psi, this eventually turned to live steam.
Feeling confidant that I am approaching a solid diagnosis of failed steam open steam traps that are dumping steam into the no pressure side of the system and causing the rest of the air above to get trapped hence all the no heats from 21 on up to 38.
As it is near the end of my day and the customer can not authorize overtime, I offer to return this morning. Before I leave I open up several supply lines on 21 and 22 and notice no steam at all, no air pressure, nothing.
I have to leave.
All night long I am perplexed about two things:
If my diagnosis is correct, why was there steam on 39 and 40 and why did I observe no pressure or steam on the supply lines of the problem floors?

I know 6 psi is way too high of a pressure setting, and I will turn it down today, but I am still bothered by my findings. The maintenance guy believes that the old pipes are plugged, I let that diagnosis lie with out comment.

Any thoughts

don_185

sounds

more like your trap has fail closed instead of open.I would
also check my fring rate of the boiler.

The pressure of your boiler will rise when you are not getting the air out.

You could have trap that have fail open and closed.And give you the type of problem you're having.

Time to start testing all traps on every floor.

David Minuz

Help Im \"trapped\"

Trap failed closed instead of open??
I have found two types of traps:
1: radiatior traps are thermostatic and normally open, with an alcahol charge that expands out and seals when steam hits it.

2: The F&T traps (hoffman) are near the condensate tank on this gravity return two pipe system, these traps are piped between the return and supply pipes. To be honest I am not sure how they work and would not know what "stuck closed" would do to the system. Please help me understand.

3: I suspect that there are other traps at the top of the risers, I have not found these yet, the maint guy tells me there is a crawl space above the 40th floor and I am going up on my next visit, to look for traps. I strongly suspect this is the case because my one riser ( one of 15 ) is the only one with no heats along its length, from floors 21 to 37.

As to the firing rate it is hard to tell, not working in the building I have no perspective. There are three boilers with power burners, they cycle as needed. The maint guy never complaines about lack of heat even in our cold Michigan winters.

Don thank you for your response, hope you can give me more insight on these traps. Exspecialy about my suspicion of traps on the end of the risers in the crawl attic.

don_185

Sure do

But not often.Its like a expansion valve on a cooling coil.
If the bulb loses it charge the valve fails closed.I think
I've may have seen two trap fail closed over the years.

I would check and see if I had any steam coming out of the vent at the receiver.If so then you could be getting what is call flash steam.Any hammering and how the water level at the boiler?

I would have to ask when were the last time the trap were replace.Most think that they last forever and thats not the case.

You need to purchase the lost art of steam heating.That will help you to understand how the f&t works along with how
to chase down the problems you're having.

Happy hunting Dave.