one or 2 pipe?

EdTheHeaterMan

I have to replace a steam boiler that is piped similar to a one pipe hot water system. there is a riser and a return from each radiator connected to one 1-1/2" steam main that is gently sloping away from the boiler around the perimeter of the basement and returns about 5 to 6" lower than the starting point before the vertical drop to the return of the boiler condensate and steam flow in same direction.. The return vertical or dimension A is only 26" (less than 1 PSI). Also there is no hartford loop. not original boiler... replaced in 1962. there are no main vents. the only thing that looks like a vent is in the supply valve. there are several small holes near the handles on each radiator. there are no traps on the radiator returns which leads me to believe that this is some kind of hybrid or modification of a one pipe system when the dead men designed it.



will there be a problem with installing a hartford loop? will the pressure equalizer of the hartford loop mess up the dynamic of the pressure getting to the radiators?..

nicholas bonham-carter

Vents in valves?

Some where there must be an exit for the air to escape.

Others will recognize the system from the valves, and recommend where the venting should be.

Double check the edr of the radiators, as this one system you do not want to over fire.

Whatever your selection of boiler, make the steam as dry as possible with a couple of risers, and a drop header with a nice increase on the header pipe size. Use a vaporstat, and a 0-3 psi gauge to verify the pressure to be less than 6 ounces. Properly sized and piped, it may show only a tiny pressure even while steaming.--NBC

EdTheHeaterMan

one or 2 pipe?

thanks for info. i suspect the original system was vapor. without the original boiler and design spec hard to tell. what is confusing me is the only vents are 12 little holes around each of the radiator valve handles. will a hartford loop bypass mess up the pressure dynamic of the system?

Rod

2 Pipe System

Hi- I’m homeowner and not an expert on vapor systems but if I had to guess I would say it looks like a Trane system. Look around an see if you can find any numbers or printing on the valves and fittings that might tell us more about your system.



Hartford Loop- The present system doesn’t have a header with an attached equalizer pipe. Without an Equalizer pipe you can’t have a Hartford Loop.



The “holes around the valve”- I would suspect that these are detents so the valve originally could be open or shut in increments.



Main vent(s) - There needs to be a way for air to escape from the steam main. How this is done depends on the piping configuration at the end of the steam main. (See attached drawing)

There also needs to be a main vent(s) on the Return Main to allow the air from the radiators to escape.                                                                                                                                                  

I think it helps to think of the boiler and that attached piping (boiler risers, header pipe, equalizer pipe, hartford loop) as a separate component. As a component, the boiler configuration would basically be the same when inserted into any type of steam system. The only difference would be that since vapor systems run at very low pressure, you would want to use a vaporstat rather than a pressuretrol and a low pressure gauge (in ounces per square inch) so you could monitor the operation of the system.



Have you calculated the total EDR load of the radiators?

- Rod

jumper

vacuum system

Perhaps the whole system was evacuated. I've seen systems with a facility to evacuate air with suction rather than steam. The device could have been a water powered venturi ejector. Somebody working on the system may have helped himself. I'd expect that enough air leaks in so that you want to evacuate at least twice a season. If your house has been insulated and tightened up your heating system could work inefficiently but still adequately warm your home.



It actually is a good idea to two pipe radiators to a one pipe system. The steam can push the air out of the radiators without any radiator vent. See Wilson patent on this site. I'd stick with current piping if your system is satisfactory now. Just add a facility for evacuating air when burner is off. Instal accurate vacuum and temperature gages. Please keep me informed.

JStar

Steam

Looks like the supply valves may have orifices in them. (Waiting for Steamhead to sweep in to identify the system). I don't have my books at home to look up the name of the system, but the hand valves should be a give away.



That boiler piping is disgusting. All of that near-boiler piping needs to be fixed. Get rid of the copper, too.



You will definitely need to add main vents to the returns at a minimum. The radiators will not require vents or modern traps.



EDIT:

http://www.heatinghelp.com/files/articles/1383/54.pdf



Might be a Broomell System. In that case, let's definitely wait for Steamhead.

Steamhead

It looks like some form of Orifice Vapor system

but you say the radiators discharge back to the steam main? That would be unusual, to say the least.



Take some pics of the way the radiators connect to the mains- let's have a closer look.

EdTheHeaterMan

Thanks.

Thanks for all the input. I will be returning to propose the new steam boiler to my customer and then take some pix of the radiator connections. Is there a way to post cellphone video on this site? I can walk around the basement and follow the entire steam mane from start to finish and look for any vents that are hidden.....



I know that air and steam don't mix and high pressure moves to low pressure and steam is lighter than air. in my minds eye.... I will follow the path of least resistance to find where the air gets out and the steam gets to the radiators. This one is puzzling me but it has worked for over 25 years and the customer wants a new boiler.



I just dont want to create a problem by installing the new boiler with a pressure equalizer and hartford loop as the boiler manufacturer diagrams specify...only to find the pressure equalizer fouled up the dynamic of the original design.

EdTheHeaterMan

Thanks.

spell check

Thanks for all the input. I will be returning to propose the new steam boiler to my customer and then take some pix of the radiator connections. Is there a way to post cellphone video on this site? I can walk around the basement and follow the entire steam MAIN from start to finish and look for any vents that are hidden.....