Vacuum to 2 Pipe Question

skifaster

Hi All,



I have just completed an energy audit of a 80 year old multi-family in NYC. This building is heated by a 200HP scotch marine style steel boiler. When the boiler was installed in 1981, the vacuum pumps were removed and F&T traps were installed in the boiler room and the system was essentially "converted" to a 2 pipe steam system. The header and the distribution pipes were not replaced. As you can imagine, there are some issues in the building including water hammer and balancing issues. Nobody in the building including the management company or the super has been there long enough to tell us why the vaccum system was removed. The super tells us that the steam traps were replaced a few years ago throughout the building and numerous engineering and architectural firms have tried to solve these issues over the years but to no avail.



I would like to help the building to solve these issues, and I am considering reverting back to a vacuum system, although this makes me extremely nervous since I do not know and probably will never know why the vacuum system was removed. I know that since the distribution piping was designed for a vacuum system the pipes, including the header piping are too small to function properly as a 2 pipe system.



Does anyone have any experience or advice for this situation? I really would like to help this building function more efficiently and help to balance the system, but I am also extremely cautious about screwing up the system even more than it already is.



Thanks for your help.

Rod

Vacuum to 2 pipe

Pictures and a sketch of the system would be a big help.

nicholas bonham-carter

200 hp ex vacuum system

as rod says, post pictures.

if the pipes were big enough to supply adequate steam to the radiators when it was a vacuum system, then they are the right size for non-vacuum operation.

early vapor systems, running at mere ounces of pressure had smaller pipes, and worked very well. the inlet valves to the radiators may have orifices or stops to allow only the amount of steam in which can be condensed. if these have been removed, then banging can result.

where does the banging occur? if in the boiler, check for improper steam piping with smaller diameters than needed. if in the radiators, then pitch, and high pressure could be the cause. what is your pressure? how is the air escaping at start-up?--nbc 

Steamhead

You would have to know

if the system was originally a vacuum-pump system, or if the pump was added later.



If the former, the return lines may not be big enough for non-vacuum operation, and they may contain lifts or other water pockets which vacuum would drain but non-vacuum operation would not.



Try to find the original plans for the system.