Two Pipe / No Traps... Vapor? What kind?

djgpro

I just purchased a 1930's duplex in southeast Michigan. I've been doing a restoration, and removed all the radiators to have them sandblasted and powder coated. They look great. It took some doing to remove the union nipples from the radiators and I had to cut out more then half of them. No biggie. I was going to get new valves and returns anyway... Now that I started to research what I need to do this I'm noticing a few things that I'm not able to completely explain. Here's what I'm looking at... 2 pipe system, steam enters at top / exits at bottom, about 6 of the 11 radiators have air vents on them, boiler was replaced 5 years ago, new pressure-trol, 2 air vents at the end of the returns before re-entering boiler. After I started to look for my replacement vents and valves, I found that 2-pipe systems with air-vents are not the norm. Purchased "Lost Art of Steam", and then went back to check on the valves I removed... Found at least some of my inlet valves had orifices. Maybe 5 / 11 orificed - but others were not (perhaps replaced?). All 11 return elbows are completely clear... not traps, no nothing. I was able to identify one of the (seemingly) original orificed valves as a "Detroit Lubricator Company" valve.

Everything I'm reading is telling me this is a messed up system. I've never run it, and its unclear if the previous tenants ran it either. I'm guessing this is a half messed up vapor system? Any idea as to what this system is supposed to be? Can I start this system up with normal valves (carefully cracked open) until I an figure out how to get orifices on them?

nicholas bonham-carter

Yes-messed up, from improper piping at the boiler, to over pressure on the pressuretrol, and who knows what else with that installer.
Why did you remove the valves? They can usually be fixed, if they leak. Metered valves are available from Mepco, but the orifices are better, while not being so convenient, as their capacity is fixed.
This system will need a vaporstat, and orifices, available from tunstall or Barnes and Jones. Later, a drop header will provide bone dry steam to make this system sing, instead of clank!
Trace the returns back to the boiler, and find out how the air can escape, as steam is rising.—NBC

JUGHNE

There is a posting on 10-21-17..."150,000 383 EDR Dunkirk/.......
you might want to look at.
Also search here for "steam orifices".

Steamhead

This is what's known as an Orifice Vapor system. The orifices allow only enough steam into each radiator to fill them 80% or so. This keeps steam out of the dry (overhead) return lines, as long as the pressure doesn't get too high.

In Lost Art, examples of this type of system are the ADSCO and Thermal systems. You can find them in Chapter 15.

The vents in the pics are likely way too small for this system. And there should be no vents at all on the radiators.

I only found one listing for Michigan in Find a Contractor- in Flint. Not sure if they go that far, but it can't hurt to call:

https://heatinghelp.com/find-a-contractor/detail/c-t-janni-and-associates

jumper

Wonder if small enough TRVs are available?

EBEBRATT-Ed

Yet another installer that installed the boiler that can't read the manual.

The good news is that with a little work this system can be made to work much better

gerry gill

EBEBRATT-Ed said:

Yet another installer that installed the boiler that can't read the manual.

The good news is that with a little work this system can be made to work much better

Yup- seems to be a problem with youngsters not being able or willing to read.

lchmb

why should they read? They know more than the old timer's..;)

Paul S_3

@djgpro turn the pressure troll down its way too much pressure

djgpro

Thanks for all the comments! Just computed my EDR... looks like I have 422 EDR hooked up to my Weil McClain PEG-45 boiler rated at 94 MBH (392 SF). The other interesting bit about this system is that the single boiler serves 2 units in this up/down duplex. I have two loops (on a common header), it appears the loops are split front / rear with each loop serving half of both units. I found a thermostat in each unit... but neither hooked up to the boiler. A third thermostat - located in the common hallway - was the one hooked up to the boiler. This does not seem good... Getting some valves tomorrow and going to try to get this system started next weekend. I'm pretty sure that the building was designed as duplex, so I'm not sure why it was piped the way it was. I'm not seeing a good way to control this thing right now.