Two pipe - No traps or orifices

TomM

I just bought a house in Pa, built in 1875.

It has a strange hybrid 2 pipe system with no traps or orifices.  I took off one of the valves to the radiators, and i expected to see an orifice, but there are none.  The valves look original b/c they have wood handles.  There are air vents at the rads, and no main vents.

Have they ever built two pipe systems without traps or orifices?   I can't really find any info on my type of system.

The system runs like crap.  The install job on the near boiler piping (circa 1980) is completely wrong.  Somebody decided to not read the directions.  It is all copper, its the wrong size pipe, and it has two T's to the header.  Also, I have this weird step down thing going on with one of my dry/wet returns.  Weird.

It looks to be mostly original piping with the exception of one radiator was turned into one pipe, and there are a few pipe plugs where some stuff was removed.

I'll be posting more pics later because my new system looks really wacky..

Thanks for the support!

TomM

pics

sorry, forgot pics

gerry gill

If all of the returns from the radiators

drop to wet returns, then how does the air get out of the radiators?

Unknown

Type

This is a steam system?

TomM

2 pipe no traps

There are air vents at the radiators. 

I can't really see how the condensate would go in the right direction without a mechanism for it.  There is also a third floor, so originally it was two sets of three radiators stacked with connected steam and condensate pipes.  (with one lone riser to the kitchen).

TomM

Original Setup

It was originally setup like this:

gerry gill

sounds like a two pipe

air vent system.

1dodson

I also have a two pipe system with no traps or orifices

I posted last week about a similar system on a 1918 house I just purchased.  Two pipes, no traps, no orifices, and each radiator is vented.   The inlet pipe (1") is just one size bigger than the outlet (3/4").  Both the mains and dry return are vented in the basement.



Reading some of Dan's stuff it seems there was a transition period between one pipe and two pipe where they didn't use traps because they hadn't been invented yet!  Steam filled the whole system.   I thought that maybe mine was a botched job from a previous homeowner but it seems to work fine, although I have no idea what the gas bill will be.



My question is if I should just leave well enough alone or made some modifications like traps or orifices.  

gerry gill

if its heating well,

and not making noises (hammering), leave it alone..if its not heating well, check air vents.

jacksonpollack

This seems to be the standard around me

Here in Central PA around PSU this seems to be the standard system. I have 3 buildings that are heated with steam and they are all two pipe air vented. No traps or orifice.



A very simple system that I have grown attached to. Most of the pipes are fairly small except for the mains so they are easy to work on. There is very little to go bad in the system if you keep everything pitched right and drained well to get the sediment out of the returns all should work well and balanced.



My only problems have been with mis-pitched radiators and return lines that don't dip into a wet return and I have had to make a goose neck type setup in them so the steam does not race through one radiator out the return and into another radiators return which will cause a balancing nightmare and defeat TRV's if you have installed them. This is because the steam will run through a radiator that may have it's TRV closed, but because the steam can go through it and vent out another radiator that intermediate radiator will still get hot regardless of what your TRV is doing.



Also make sure your returns are clear and flowing it can be hard to recognize because a radiator will still get hot and the condensate can drain back into the supply side, but it does not work well and all the condensate draining back into supply main will cause problems because it is not sized to deal with it.  Crazy hammering in the main is normally the give away. I have gone to some pretty bizarre measures to get the mains clean. Unhooking radiators and hosing down each one works well or a large wet/dry vaccum can do wonders. Once you get them clean you are probably good for the life of the pipes, though I am sure many would disagree. I figure it took 80 years to get that bad, by the time they are filled again the pipes will probably have holes rotten in them.



And yes I have had to redo the near boiler piping on two of the places because the last installer did an awful job and did not want to deal with the hassle of 4" piping so they only used 2-1/2", probably the largest they could thread. After all was put the manufactures spec. the heat bill went down 1/3 and tenant happiness increased dramatically.



Hope that helps, the system can work very well once you get the hang of what to look for and how to fix it.