Vertical Cooling Legs for Drip Traps.....Possible?

JUGHNE

I have a 2 pipe system down fed from an attic main.
I believe the branches come off the top of a 3 to 5" main.
The drop branches go down 2 floors, so there is about 20' of 1 1/2-1 1/4" vertical pipe.
There are 28 drip traps alone (1/2" WW 702's which all will get new B&J 1972's).

Every where I read about the importance of the 5' cooling for these traps to have when used for drips.
Most are connected directly on the tee above the mud leg for each drop, some may have 1' or so of horizontal piping.
This is a 1933 install. I am assuming the "Dead Men" knew what they were doing.

My best guess is that they relied upon the 10 to 20" of vertical 1 1/4" pipe below the rad valve connection to cool the condensate. Also the 4-6" mud leg would be full of water to dissipate some heat?
All mud legs were completely full of mostly solid sediment up to the branch tee for the trap, (4' cheaters needed).

These are mostly installed in classrooms.
Adding the horizontal cooling leg is not very feasible, nor is F&T installation.

Any pitfalls to watch out for?

EBEBRATT-Ed

Just clean out the muck. A strainer is probably a good idea if you can. I like to take new strainers apart and "never seize" the strainer screen bushing before the get cooked, easier to take apart and clean the next time. I think your fine with the vertical drop acting as the cooling leg

JUGHNE

All the mud legs got cleaned. It took a 1" pipe scrap hammered up into the 1 1/4" nipple. Some would then "pass" black turds of sludge out thru the 1". I don't think the grandson was impressed but he was glad when we were done.
Only a few trap bodies had some sludge in them.
Did find some 1932 trap elements in hidden/covered up drip traps.
Thanks for your input.

gerry gill

were assuming here that everything has worked fine for the last 90 years? if so is there a problem here?

JUGHNE

I have only been around this for one heating season.
It sorta-kinda has been working, making heat.
Short cycling boiler....
Air venting thru buried "dry returns" is questionable.
Am adding air vents to the mains where feasible.

There has been a lot of steam coming out of the cond pump vent. So much that it was considered the norm. The vent was extended with makeshift piping to get it to sump pit.

Radiation removed as building envelope improved.
Drip traps at those points were ignored as they were considered unnecessary. (those had the 1932 elements yet).

Drip traps unseen above suspended ceiling as building rooms were repurposed.

It is one of those systems one would try to save.
Very small school district 50 miles away, a short hour drive out here. But well beyond my (old guy) normal range of travel.

I hope to show them some improvement for their money.

EBEBRATT-Ed

It will be worth fixing. Every lb of water leaving through the condensate vent is replaced by say 50 degree cold water. So the loss is the cost to generate 1 lb of cold (50 deg) water into steam about 1032 btu for every lb lost

JUGHNE

The seal went out on a 5 year old condensate pump last year.
Not only steam but chemicals were added just ahead of the pump inlet. They have not only cut back on chemicals but now chase the mix thru the pump with water equal to the blow down of the 2 LWCO's.....better than it was but hopefully with out fresh water added in the future the treatment could be almost eliminated.

There are 6 dry returns coming into the boiler room.
As I have a chance to modify them I add a tee with a high vent pipe. This will tell me which return is passing steam. (hopefully none when all the new traps are in, there still could be some traps hiding somewhere in the building. I have tracked down every pipe but have not visited the main attic. Don't know where the access opening is. No one else does.
The dead men did this vent/steam indicator in 1933 to 2 of the returns.

EBEBRATT-Ed

Good idea with the vent to show blowing steam so simple like 'why didn't I think of that"

Attic supply is usually it sounds like the old Mills system. Probably only one vent in the attic at the end of the main.

JUGHNE

Thanks Ed,
The blueprint is fairly detailed and shows nothing in the attic other than pipe and fittings.
I believe they relied upon drip traps and rad traps (all1/2") to vent all the air.

Looking at several book drawings of 2 pipe attic supplies with pumped returns they rely upon traps only for air venting.
None shone in the attic.