Mystery Steam System

GW

Can anyone help me figure this one out? It's a little bit of two-pipe and a little bit of one pipe.

All of the rads have two pipe and traps.

All of the rad returns come back to two return mains that don't have an f and t at the end. Just a basic main vent

The two supplies loop around the basement and basically connect at a tee, and the branch of the tee runs back to the boiler and connects to the f and t above the boiler.

We we there fixing some gas leaks today, but this caught my eye.

Thanks, Gary

Steamhead

That system has a non-pressurized return. The F&T trap on the steam main drip turns the "A" dimension into a "B" dimension. The dry return drips are of course "B" dimensions as well.

I'd bet at one point there was a Return Trap on this system. Were you able to see any original hardware that had names on it?

The main vent is pathetically small. Is the pressure limit a Pressuretrol or a Vaporstat? It should be the latter.

GW

Thanks, I didn't get readings off the big trap above the boiler. That's an f&t? I havent done any 2 pipe in all my days. I'm ok to good with one pipe.

It seems like the one lower return main at one point went into the "other" return drop at one time based on that tee that's plugged.

The boiler seems like 1980s vintage, Peerless G761. It would be nice to know what was there before the Peerless went it.

Steamhead

Barnes & Jones made that F&T. But I seriously doubt it's original. Next time you're there, look at the radiator valves and traps to see if they have names or trademarks on them.

GW

Yes i'll take pics next time i'm there. Also, it's a basic Pressurtrol. Thanks, Gary

JUGHNE

Steamhead, is the F&T needed? Could the end of steam main drips just be dropped down into the wet return ahead of the HL?
Then with venting added above that would that improve things.

Now the F&T is to vent air out of the mains and to where?

The dry returns could certainly stand more venting? In theory there should be no steam in them because of rad traps and actually the open pipe should work?

I have not seen that LWCO/fill valve before, (but then I have not seen a lot). The time delay in the control circuit is interesting. It must be a delay on re-make of power......when the LWCO cuts the burner circuit the timer starts after power is restored? This may have been an attempt to avoid rapid short cycling of burner and/or give a little time for slow condensate to return before re-firing the boiler, dropping the water level again and calling for overfilling??

Fred

@JUGHNE , That's the MM #101 Auto water feed. I don't see the LWCO?? May be on the other side?

JUGHNE

So that is a 24VAC powered water valve?? The LWCO that calls for it to work is as you say somewhere else. So the time delay could be a delay on initial make of power to delay the water fill from getting ahead of the condensate return ...of course the burner would be off until water level rises from condensate return or fill valve does its job. That control is adjustable, but I cannot see the timing range. (they come in 2 ways, delay on make or delay on break).

Fred

Yes it is a 24VAC water valve.

Sailah

Steamhead said:

Barnes & Jones made that F&T. But I seriously doubt it's original. Next time you're there, look at the radiator valves and traps to see if they have names or trademarks on them.

That's one of our "old" old style T series traps. Hard to tell based on the lettering but it will be T41 T42 etc. still make parts for them. Send me an address and I'll send you a rebuild kit. I'll walk you through the rebuild but it's pretty basic.

We'll make a 2 pipe guy out of you yet!

Peter

Steamhead

JUGHNE said:

Steamhead, is the F&T needed? Could the end of steam main drips just be dropped down into the wet return ahead of the HL?
Then with venting added above that would that improve things.

We probably don't need the F&T. Many Vapor systems such as Trane and Hoffman simply dripped everything as you say. But until I know more about that system, I won't go that far.

JUGHNE said:

Now the F&T is to vent air out of the mains and to where?

Nowhere, unless there's a connection between the F&T outlet and the dry return. If there is no such connection, it's just turning the "A" dimension into a "B" dimension- which was intentional in some Vapor systems, notably Webster.

JUGHNE said:

The dry returns could certainly stand more venting? In theory there should be no steam in them because of rad traps and actually the open pipe should work?

I like to have a proper vent there so if a trap fails, we don't lose a lot of steam. At least one Gorton #2 on this one.

JUGHNE

So Steamhead, more Q&A time if you please, (I think others have these questions also as to what determines that any 2 pipe system may or not be a vapor system).

First I assume that the pressure must be limited by a vaporstat to single digit ounces operation......6 to 8 maybe.

2nd I would guess that the piping must be generous is sizing all the way from boiler to radiator in order for the pressure drop to be at a minimum.

3rd.....there must be an orifice in the inlet valve to strictly limit the steam delivered to that radiator almost eliminated the need for a trap or an orificed trap on discharge in lieu of orficed inlet.

4th.....air elimination thru orifices must be slower than the standard trap. So to vent the steam main there are cross over traps into the dry return and all air is removed thur the dry return air venting......which in some cases seem to be only one vent in the boiler room.........where as for the same volume of piping in a one pipe system we could be having antlers of multiple Gorton 2.

If the boiler is quite oversized or pipe insulation is missing or incomplete then the vaporstat would be short cycling quite a lot??

If I have a one pipe system running well on 8-12 oz pressure would it be considered a vapor system?

What keeps any 2 pipe system from being considered a vapor system??

That's not even 20 questions We all thank you!!

GW

I'm sorry to say I dont have a reason to get back to the home, the gas leak issue is buttoned up..

Peter thanks for taking my into your flock

Steamhead I could chime the nice fellow homeowner again, that pitiful vent in the pic is venting the entire system? I presume that is the case. Any wild idea how much fuel is wasted with such little venting?

So, the f&t was added by the 1980s guy? It's not needed?

Thanks, Gary

Steamhead

First thing to do is change that vent. The house will heat more quickly. Also check the pigtail under the pressuretrol to make sure it's open, and crank it down.

The owner would experience better comfort, lowered fuel consumption, or both.

Leave the F&T for now, unless it's not working.