Venting at elbow supply valves

Orple

As I noted in my last post, I have one horizontal main that is vented at the end of the condensate return, but have supplies running off the main that are between 9' and 14' long and which have no vents prior to the radiators they feed. Currently, they are simply vented through the radiators themselves.



I know that one option is to tap the supplies right before they rise the radiators, although I'm a little nervous to do that as I haven't ever tapped a steam pipe, so I'd like to avoid that if possible. Moreover, some of them run over the ceiling of a finished part of the basement, and so are inaccessible for tapping.



I've also read about Frank Gerety's solution of replacing the elbow right before the supply value with a tee, and popping vents above that. My problem is that all of my supply valves are elbows (out of the floor and directly into the radiator). I realize I could replace all of the elbows with tees and straight supply valves, but that would be both costly and wasteful.



I'm wondering if anyone knows of a good solution to this problem. Is there some way to re-pipe while reusing the elbow valves? I realize it's a long shot (every way I think of it doesn't work), but if it worked it would have a lot to commend it over the other two alternatives.

MDNLansing

Tap It

Drilling and tapping in an elbow isn't all that hard. Especially when you are talking 1/2" holes.You can practice a few times in a smaller fitting on a workbench before doing the real thing. Tap and die sets aren't that expensive either. Most average handymen can actually do it pretty easy.



If you are totally against it though, do the elbows on the radiators have nuts so you can take them off? If the will separate from the radiator easily, you could take them off the radiator and off the supply pipe and have you local hardware store drill and tap them for you. Most places like ACE Hardware and local mom and pop shops will thread and tap for you.

Orple

Update

Actually, looking at it more carefully, I don't think tapping the supplies is an option, at least not from the basement side. The supplies run in the basement rafters almost immediately under the first floor floorboards, so there wouldn't be a place to put a vent anyhow even if I could get a tap in there.



Also, to clarify, the elbows feeding into the radiators are the supply valves. Is it possible to tap a supply valve?



I'm certainly willing to tap if necessary; I've run taps before, just not on steam pipes. I'm sure I can get over my wariness.



If I can't find a way to vent somewhere around the supply valve, though, I think my only choice is to vent through the radiator.

MDNLansing

Supplies

Are these supplies you are referring to the pipes that feed steam directly to the radiators from the mains? Each one leaves the main with a T and go straight to a single radiator?

Orple

That's correct

It leaves the main, runs for between 9' and 14', then pops up and feeds a single radiator. There are two that feed the second floor, different only insofar as they have a significantly longer riser. But yeah, one supply per radiator.

MDNLansing

Don't Need Vents

Are you having troubles with these radiators heating up or the radiators vents whistling? Typically, you don't need to vent the radiator take offs. As long as the mains are vented properly, you should be good. What problems are you having?

Orple

The back story

The problems behind everything (i.e., that which I'm really trying to fix) are as follows:



1. My system is really noisy when it starts up. I don't mind, but the wife does, and so that means I do too (officially). The vents on the radiators seem to be doing all of the heavy lifting, which makes me think that I'm not heating very efficiently. If the system were better vented, my sense is that it would heat up faster, more quietly, and more efficiently.



Note: my main vent is fouled and needs to be replaced. That is the main culprit in all of this, and I'm the process of fixing it. I just thought that the other supplies needed to be vented as well; I seem to have misunderstood.



2. The second problem is that I'm running through a lot of water and running at higher pressure than I think I'm supposed to. My pressuretrol is currently set higher than it should be (but I'm also in the process of fixing that in another post), but I noticed that the stock "internal syphon" gauge runs at like 27 lbs of pressure when the boiler is running at full throttle (I read the posts that say to ignore that, but those posts indicate 15 lbs or so, and this seems quite high), and I'm finding I have to refill the boiler about every week. So something's wrong, and I think it's that making the radiator vents do all the venting is making water shoot too far through the system and its making all the vents spit whenever the system is on (it's not because I'm overfilling).



So that's the extended back story. If I don't have to vent the supplies off the main, that's good news. I take it that I would take the supply volume into account when sizing replacement radiator vents though?

MDNLansing

Start With Venting

Get lots of vents on the mains. The end of each main should have at least one good sized vent on it. Some systems use a single vent at the return which is OK too, but make sure you have plenty of venting going on there. If you only have one place to vent from, put at least 3 or 4 Gorton #2's on it. Try to get the air out of the mains as fast as possible. Get an antler with some big high quality vents on the mains as soon as possible. Then, reassess the problems.



If you still have issues, move of to the radiators. Radiators you want to vent slowly. The Gorton website has a pretty useful graphic to help size them, but it can be some trial and error. You will find yourself moving them around and trying them in different locations. Once that's done, reassess the problems.



As for pressure, this is a must to take care of. I doubt you are actually running at 27 psi. Either the gauge is broken or its plugged up with gunk. I would make it a high priority to replace the gauge and see exactly what you are running at. They are easy to swap out and not too expensive. You say you have a siphon gauge, is this a vacuum system? If it is, get a low pressure combination gauge, if it's not, get a regular low pressure gauge. No matter what, you need to figure out the pressure. Running anything over 2 psi is costing you a ton of money and is totally unseeded. It might also be the reason for the water loss and noises. Once you know exactly what pressure you are running, you will know what to do with the pressuretrol.



As for venting the take offs though, don't.. It's unneeded work and expense, and will probably just make a huge mess spitting water all over the place.

Orple

Vents

Yah, there is only the one main vent right now, which--if I don't need to vent the supply lines, makes sense. The main line is only 16' long (@2"), with a 15' return (@1"), so it shouldn't take much to vent it. I've been working on the calculations for this in another post here, and it's definitely a high priority.



The posts I read about this said that the "internal syphon" said it came stock with some boilers (mine is a Burnham), that it was a safety precaution, but that its reading didn't mean much. I have no idea what to make of it but it does put me on edge a bit. From what I recall, it does move quite a bit based on whether the boiler is on or not; I'll update with its reading after the boiler's been off for a few hours (I think it goes back to 0). In any event, putting another pigtail on with a 0-3 psi gauge (and perhaps a secondary pressuretrol) is also high on the priority list. My guess, however, is that the "internal syphon" gauge must be something completely other, because the pressuretrol should never let it get that high.



Thanks again for all your help on this -- this has been very helpful.

rmoore007ri

gauge on the Burnham Boiler

If the gauge on the boiler is 0-30 psi labelled "Internal Siphon" that just means you do not need to attach the gauge using a pigtail. It does not mean anything special about the boiler. It is a code issue. ADD a 0-3 psi gauge on pigtail. It is the only way to watch what is going on.



My one pipe system has two mains (33 ft and 13 ft) with venting about 15 inches back from the ends of the returns before they drop. Lots of venting. Get that piping up in the air 15 inches or so and pitched so condensate does not get trapped. (Venting near the ends of the mains would have been a nightmare.)

rmoore007ri

two gauges

Here is pic of my Burnham using the original tapping where the single "Internal Syphon"

gauge was. Each on its own pigtail. I cannot stress enough what a diifference that 0-3 psi gauge has made to understanding what is going on.

Orple

Interesting....

Very nice setup. It looks like you have the same basic boiler setup as mine, except that yours is actually set up the way mine should be. Just two questions:



1. I noticed that you popped the gauge with the internal siphon on a pigtail anyway, even though you said that it indicated that a pigtail was not required. I take it that this was just an extra precaution, or is that the extra piping negated the internal siphon?



2. We might have a different thread in the factory gauge. It looked to me like it would be easier to run the 0-3 gauge off the same line as the pressuretrol. That shouldn't make a difference, correct?



I think I know the answers to both of these questions (yes just a precaution and no shouldn't make a difference) but figured I'd check to be sure.

Orple

"Internal syphon" gauge update

I should probably just start calling it the "high pressure" gauge or "0-30" gauge or even the "useless insurance gauge" or something.



In any event, I checked it last night after the boiler was off for a few hours, and it read 15 psi; it reads about 27 psi when the system is running. So it *is* moving, but I can't imagine it's accurate, as the pressuretrol should have cut it out if it were.



I'll have to wait until I get the low pressure gauge installed to figure out what's *really* going on, but any guesses in advance? If it sounds like the "useless insurance gauge" is wonky, perhaps I should build its replacement into my gauge re-piping plans.

Hap_Hazzard

That vent should be higher.

To avoid water damaging the vent, you should mount it at least six inches above the main, if you can get it that high. If not, do the best you can.