BASE-RAY lateral won't heat

PEvans

This is 2-pipe, pumped condensate return, not a "vapour" system as far as I know.

One zone is split between a section with regular radiators and a section with BASE-RAY baseboards. The former works fine; the latter is not heating at the moment. Here is a diagram:

Steam System Zone 1 Layout.pdf

The only air vent on the entire system is the condensate receiver at atmospheric.

The traps on the radiators are all new.

The condensate return from the BASE-RAYs has this 17" loop or p-trap going into the condensate manifold. Is this something BASE-RAYs need, or some other reason why it was built this way?

My system distributes steam in startup at a steady 0.25 psi and everything heats up but the BASE-RAYs. It operates between 0.10 psi cut-in and 0.6 psi cut-out on a VaporStat. These are all values read from the low-pressure gauge at the boiler. Is this pressure just too low to get the air from the BASE-RAYs over that loop? If so, what should the pressures be?

Jamie Hall

That condensate loop is your problem. It's supposed to have a crossover trap above it. How else is the air supposed to get out of it?

If the rest of the system is working alright, I'll not mumble about using F&T traps as main vents… but just let me say that they are lousy main vents.

EBEBRATT-Ed

Why a zone valve with only one zone?

Why with traps on the CI radiation do you also have an F & T on that return in the basement your "double trappped" get rid of the F & T.

The base ray is not working because the air can't get out do to the down and up return creating a water seal as @Jamie Hall mentioned

PEvans

@Jamie Hall Can you provide more detail on your recommendation? I'm not familiar with a crossover trap or how it would be implemented here.

@EBEBRATT-Ed There is a second zone not shown. Yes, I noticed when I made the diagram that the F&T trap in the return makes that side double-trapped. The other zone is the same, with traps on the radiators and an F&T trap in the return near the boiler. That stuff all seems to work. Is it a big enough deal to warrant taking the F&T traps out?

Anyone: I agree there is no obvious way for the air to get out of the BASE-RAY lateral. That said, this lateral was put in in the 1950s. They must have had something in mind and it must have worked when it was built. Moreover, they liked the return so much it was rebuilt like-for-like to replace the section running on the floor; the old pipe is still there. There is room to run a return without the down and up/water seal, they just didn't. So I'm still wondering why it was built this way.

Also, the BASE-RAY radiators have heated up during my time. I'm not positive, but it could have been with my old Pressuretrol, perhaps the system was operating at a higher pressure.

Thanks very much.

Jamie Hall

The higher pressure could do it. 17 inches isn't much of a seal — half a pound will blow it. Not the right way to go about doing things…

EBEBRATT-Ed

Yes the higher pressure could make the base ray heat.

Look, when something is wrong (double trapped and water seal) no one on earth can tell you weather is might work under certain circumstances.

The only thing we can tell you is what you have asked. Why doesn't it work?

Double traps don't work as well as single traps. Look up "master traps" on this site for more information.

The loop seal will prevent air from getting out of the base ray unless you run higher pressure and force it through. Not the way to go for comfort and efficiency

PEvans

I used to have steam blasting out of that condensate receiver vent. I have worked on the traps and now it is not even warm. So I think the traps are trapping OK if still wrong.

It's easy enough to try higher pressure like what the Pressuretrol may have been doing. I agree not the most comfortable or efficient, and I know the rest of the system is happy with my present settings.

What is a "better" fix to correct for the water seal? A vent of some sort on the return before the seal?

Again, thanks.

Jamie Hall

Why do I have this feeling that at least someone has been there before and tried to "fix" things?

The simplest way to get rid of the water seal problem is to… get rid of it. There should never be steam in those return lines anyway. However, if you do that you need traps on the outlets of all the radiators — and on all the Baseray units. I suspect that you still need the F&T at the end of the steam main which goes to the Baserays, but you should also have a decent main vent on there as well (Gorton #2 maybe)? You really shouldn't need the other F&T traps on the returns — and I honestly can't figure out what the F&T on the line from the header is doing… or even really why that line is there at all.

PEvans

@Jamie Hall I already have traps on all of the radiators, including the BASE-RAYs.

I think you and @EBEBRATT-Ed are right that the other returns (Zone 1a in the diagram, but also Zone 2 not shown) don't need traps as all of the radiators have them. At least for now they don't seem to block the returning condensate, but sure, those traps could fail closed.

The main steam header and the two zone valves all have drips with F&T traps. Those traps seem needed to me, and one of these traps had failed and was passing a lot of steam (fixed now).

I think there is enough headroom for what would be basically a drain from the BASE-RAYs to the condensate manifold, but it would no longer have the 6' straight down drop if that is important for anything.

I guess it is possible that a prior iteration of this system did not have the pumped condensate return. I sort of doubt it as the headroom is pretty limited; beyond that I have no way to know. Anyway, I have seen other posts here about BASE-RAYs and using water seals to keep steam from backing up into the BASE-RAYs. I did not and don't really those posts.

Jamie Hall

There is nothing wrong with a water seal on a two pipe system return. In fact, it is a great way to allow condensate to pass from the steam main to a corresponding dry return (a true dry return, not a steam main continuation). Provided two things: first, that there is also a way to vent air from the steam main, either into the dry return with a crossover trap or through a main vent, and second, that the depth of the trap is enough to maintain a seal at the maximum steam pressure allowed in the main. Which is our old friend 28 inches per pound psig.

A drip into a wet return connected to the boiler won't pass steam either (but does need to be vented if it's from a steam main, not from a dry return). However, a drip from a steam carrying pipe into a pipe going to a vented condensate receiver or boiler feed tank will have to be trapped, as there is no pressure to keep the steam from moving through. Introduction of a condensate or boiler feed tank into what were wet returns can cause havoc unless those traps are added.

You really have to go back to square one. What are the pressures in various parts of the system? Where will water stand in response to that? How does the air get out? How does the water get back to the boiler? Where do you want the steam to go? Where do you NOT want the steam to go, and what's to prevent it from going there?

EBEBRATT-Ed

As far as the base Ray goes if you piped in a tee on the drop above the water line in the return dropping to the loop seal and put a 1/2" thermostatic trap on this tee then pipe a 1/2" pipe over to the condensate receiver and tied it into the receiver or into the condensate receiver vent line this would eliminate the air from that loop

PEvans

Could I put an air vent on one of the outlet tappings of the BASE-RAY steam main drip? I saw this idea at p. 237-238 of TLAOSHr.

(assumes I can get the plug out, of course)

EBEBRATT-Ed

An air vent on a tee at the top of the 73" riser might work ok. Check the nearby F & T some traps have 2 inlets and 2 outlets and the unused tapings are plugged. If you have a spare outlet tapping you might be able to get the vent on there, may not work as well though

PEvans

A little off topic, but any suggestions on getting the plugs out of the unused tappings on F&T traps?

EBEBRATT-Ed

If it is a struggle take the trap out and put it in a vise to get the plugs out. Most traps have or should have unions around them

PEvans

Good call. Actually, this trap looks like it does have unions; not all of mine do. Better that than breaking the pipes…

PEvans

What would be a good choice for this air vent? "Fast?" Drop-away pressure? Adjustable? Air check valve?