Hybrid Steam System? or knuckleheads at work?

Thad English

My wife and I just bought a 100 year old stone house in Philadelphia with steam heat. The Peerless boiler is only 3 years old and the 2-pipe system was making some water hammer so I ordered Dan's book to educate myself on steam heat. Now I have a couple of questions with which hopefully some knowlegdeable people can help.
The steam system is a 2 pipe system but the radiators all have steam valves (which hiss, I might add, when the system kicks on) similar to what is pictured in the single pipe system. In the book there is a diagram of a 2 pipe system and it outlines a radiator with a hydrostatic (?) valve that allows air into the returns but not steam. I examined my radiators and there are just straight pipes coming out on the return side and connecting with the returns. There is nothing that resembles any housing for any type of valve. The book also explains that the 2 pipe system was more desirable because everything vents in the basement and there are no vents in the rooms. (The steam valves/vents on the sides of the radiators in my house seem to contradict the book.) This does not sound like a 2 pipe steam system that is working properly. Is there a reason for someone to have made these changes? (Aside from them not knowing what they were doing.)
And if not, can anyone tell me who I need to call in Philadelphia to get the system working the way it was designed?
Thanks,
Thad

Unknown

2 pipe air vent

See if it's one of these. Figure 2 page 228.

Noel

Jamie_6

Hi Thad! My name is Jamie Pompetti from Pompetti Heating & Air Conditioning, Inc. in Media Pennsylvania. I just wanted to let you know that I am about 10 miles south of the Philadelphia International Airport and if I could be of any assistance to you please call.

Jamie Pompetti

Pompetti Heating & air Conditioning, Inc. 610-565-4778

www.PompettiHVAC.com


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Steamhead

Noel's right

The 2-pipe air-vent system was a transitional system, between one-pipe and Vapor. It was more expensive to install but often didn't give the owners the control of heat in individual rooms the way the later Vapor systems did. But I still see this type of system once in a while.

It's best to keep the pressure very low (1 PSI or less) in this system, so the steam won't get too far into the return lines and cause banging. A Vaporstat will do this job, though it's expensive.

Vent your steam mains like a one-pipe system, but don't vent the returns at all (unlike Vapor) since this will let the steam get into the returns.

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Unknown

2 pipe steam?

What you have in the building is a 2 pipe air vent system.

This piping system is the prcursor to 2 pipe steam with steam traps.

The two pipe air vent ystems came into being about 1880, about the time working automatic vent valves were invented.

This system operates under the rules of a 1 pipe steam system.

Many of these steam systems had very large steam mains and therefore were set to operate at as low 6 OZ. steam pressure.

You need to make sure all the vent valves operate and that you have main vent valves on the end of the steam mains in the basement.

These steam systems must vave insulated steam mains or you will have operational problems.


jake