Illinois Vapor Heating Improvements

bmakenas

Looking for some advice on an Illinois vapor heating system. Currently there are no air relief vents except for at the heat retainer. No air vents on the main steam line or returns, except the dry return traps. The heat retainer doesn't appear operational and being that it appears to be the only real means of removing air from the system, was wondering whether its removal and replacement with an air vent instead would be just as good, similar to the Gorton #2. In addition was considering adding a couple air vents near the dry return traps to assist in moving steam faster through the steam supply mains. Attached is a diagram of what I was thinking. Any advice or suggestions greatly appreciated. Thanks.

Jamie Hall

By "dry return traps" do you mean a steam trap -- radiator type trap -- going from the end of the steam main into the dry return? If so, they will vent more air (that is, assuming they are working -- you might check!) into the dry return than any vent would vent. I would keep them, and put a couple of #2s at the end of the dry returns where the heat retainer was.

Steamhead

The Heat Retainer IS the air vent. It is responsible for venting air from the entire system. What makes you think it isn't working?

The traps on the dry return (called "crossover traps") vent the air from the steam mains. Air passes into the dry return and out the Heat Retainer.

If there is a vacuum check on the Heat Retainer, I'd remove it. Beyond that, make sure the crossover traps are working. If the steam mains vent slowly, you can install higher-capacity crossover traps.

bmakenas

Thanks. Dry return as in the end of the supply mains where they return to the boiler room. There are two Illinois 1G radiator type traps where they return into boiler room. One return is hot while the other cold. I'm assuming the cold has a failed 1G. I was considering adding an air vent alongside each.

bmakenas

Steamhead, Understood however, I believe the retainer isn't working based on visual observations, which indicate a dry, sediment filled and corroded interior. If this is the case and the retainer is the air vent, couldn't it be replaced with a Gorton or similar? I will have the Illinois 1G's rebuilt or replaced on the crossovers. Thanks.

nicholas bonham-carter

I would think that the crossover traps are a secondary defense against steam getting into the returns. This could indicate that one or more radiator traps have failed, and are allowing steam through. Feel the discharge of all the traps and get some replacement elements from Barnes and Jones.--NBC

https://heatinghelp.com/assets/documents/314.pdf

Jamie Hall

bmakenas said:

Thanks. Dry return as in the end of the supply mains where they return to the boiler room. There are two Illinois 1G radiator type traps where they return into boiler room. One return is hot while the other cold. I'm assuming the cold has a failed 1G. I was considering adding an air vent alongside each.

Not necessarily. The dry returns really shouldn't be hot. Warm, perhaps. Hot, no. Cold or cool is ok. If the dry return is definitely hot, you have steam getting into it. It could be that the crossover trap to that return has failed open. It could also be that one of the radiator traps associated with that return has failed open -- in which case it's return pipe will be hot too.

In an ideally balanced system (yeah, right...) the crossover traps will vent air until they are hit by steam, and then close. They don't handle condensate at all. The radiator traps handle air and condensate. The condensate will be warm to very warm (usually!). Thus the radiator returns may be warm, but the outlets of the crossover traps should not be.

Jamie Hall

And PS -- don't add an air vent at the crossover traps. Just Don't Do It. If you feel you need more main venting, put it where the air eliminator is near the boiler.

A trap will went more air than even a pretty good menorah of #2s will.

If you ever decided to get real fancy and go to a partial vacuum system, vents anywhere except at the boiler will be a real problem.

Never mind you just don't need them.

bmakenas

Thanks all. Appreciate the input. Planning to replace/rebuild the crossover traps first then hit the radiators. Replace and or add an air vent at the retainer. Merry Christmas!

nicholas bonham-carter

Maybe it would be wise to do them all at the same time, so any leaking radiator traps do not close other traps by allowing steam into the returns.
Get some cheap harbor freight large open end wrenches, so you can fit the flats of the trap covers exactly, and tap on the wrench end as you apply constant moderate force to unscrew them.--NBC

bmakenas

I have felt all the radiator return risers upstream of the main return connection in the basement and none were hot. Some were warm, therefore I think I'm ok for the moment on the radiator traps still being operational. Or at least traps do not appear to be in a failed open position.

Maybe not the recommended way, but I have found a 24 inch adjustable Crescent wrench with a 2 inch steel pipe extension off the handle side, some delicate words of persuasion to the trap then a gentle push/pull will easily open any seized trap cap.

Dave in QCA

If I was a devious person, I would tell you that you should remove your heat retainer and replace it with an assortment of vents as you have described.... AND Send the Heat Retainer to ME!!!.

But I'm not, and so I have to say you're trying to solve problems that you don't have. By the way, do you also have a Return Trap? Or, just the Heat Retainer. I note that Illinois Vapor later changed the name of the Heat Retainer to the Air Eliminator, which was consistent to the rest of the industry. On a side note, I have been restoring my Dunham system for about 3 years, and have been searching for a Dunham Air Eliminator, but as yet, have not found one. Someone, thinking that it didn't work, (most likely because he didn't understand it) removed it and threw it away!

You have indicated that it appears that your radiator traps are all working as they should. For your crossover traps, which vent the steam mains, they should both get HOT, but the pipe downstream about 5 feet should remain much cooler, perhaps a bit of warmth, but not so HOT that you can't hold your hand on the pipe. If it is TOO hot, then the trap has failed partially open. If you find you need to repair your Crossover traps, I would use original parts only, not a Tunstall or Barnes & Jones cage unit. The reason being is that the cage units will not pass as much air and fast venting of the mains is important. Cage units on the radiator valves, if needed would be fine.

The purpose of the Heat Retainer / Air Eliminator is to allow the air to freely vent from the system, but not water. Under normal low pressure conditions, the condensate will return to the boiler by gravity. However, if the pressure rises to the point that it cannot, condensate can back up into the return lines and the float valve in the Heat Retainers will close to prevent the loss of condensate out of the vent port. Now, it is interesting to note that a Gorton 2 and a Hoffman 75 both have float valves, but I believe most would report that they usually do not seal tight and will typically leak water if the condensate is backed up. In this regard, simply cleaning out the devise you presently have will give you the best service possible. Remember the B dimension, roughly 30" for every pound of pressure at the boiler. And so, if the boiler pressure rises to 1 psi, the water level in the return piping will be 30" higher than the water level in the boiler.

Regarding the vacuum check disk, if it is still present on the outlet of the Heat Retainer, I have restored my Dunham system to vacuum operation and observed that venting of the air as the boiler starts to produce steam is greatly facilitated because the amount of air in the system is greatly reduced by preventing the air from reentering the system when the boiler shuts down.

bmakenas

Thanks Dave.

The dry return traps, Illinois 1G's, were replaced. The return pipe too and immediately after the traps are very hot. The vertical drops down to the condensate are hot and decrease to warm when they turn to the horizontal position.

There is an F&T trap along with the heat retainer. The trap does not have a sight level so I opened some taps on both the F&T and the heat retainer and both appear bone dry. I did check the air vent at the top of the heat retainer and it was allowing air to escape, although it seemed minimal. Most radiator returns do not get warm at all, likewise for the return main. Seems these should get at least warm with condensate running through them. I'm thinking there may be air trapped within the radiator return portion thereby not allowing free movement of steam, which in turn only partially heats some of the larger radiators.

Are there rebuilt kits available for the old Illinois F&T and retainer?

In terms of the retainer vacuum port, was your intent to indicate for it's removal? Couldn't tell by your last comment.

Thanks.

Dave in QCA

Can you post pics of what you are calling an f&t trap? I suspect it is actually a return trap. Travelling today, I have limited ability to reply.

bmakenas

Pics attached show both the F&T and heat retainer.

Steamhead

Dave is right- that's a Return Trap. It is basically a pressure-powered pump that can return condensate to the boiler if the pressure gets too high for it to return by gravity. There is a very good discussion of this unit in chapter 15 of "The Lost Art of Steam Heating".

On oil or gas firing, the vacuum check on the Heat Retainer sometimes allows vacuum to form before all the air is out. This can block steam circulation. Some of us are experimenting with mechanically induced vacuum on systems like these, but for now, I'd remove the check.

Dave in QCA

Yes, agreement with Steamheads comments, he beat me to the punch. You do not know howvlucjy you are to have an intact vapor system. Many times the equipment is yanked out because people don't understand it's operation. I am sitting in an airport and travelling today. There are some materials on the Illinois system in the heating museum area. I will try to find the link and email it to you, as well as a description of operation.

The one point I disagree with steamhead is on vacuum operation. Vapor systems will work very well on vacuum, and were intended to do so for firing on gas and oil, as well as coal. I'll explain more later. The vacuum devic. consists of a thin disk that is under the cap with holes, whe the air vents out.

bmakenas

Thanks Guys.

As earlier indicated, both the return trap and retainer are bone dry, therefore I assume they are non-functional at this time, other than a little air being relieved from the retainer. Currently there is a Dole #4 'Quick-Vent' on the retainer. It's not whistling, but I did pull the vent and some air was pushing out of the retainer. Blowing into the #4 vent indicated air was passing through. I may replace the vent with a newer vent.

As far as the return trap and the retainer, can these be rebuilt? Are parts available for these old Illinois parts from other manufacturer's? Other than the dry return and radiator traps, I haven't seen any Illinois replacement parts in my amateur search.

Thanks.

Dave in QCA

They are supposed to bone dry. I will expland later. On the ground briefly in Minneapolis

Dave in QCA

@bemakenas There is an Illinois Heating System brochure posted in the Heating Help "Heating Museum" area. It appears to be from the 1940s. It does not cover the Heat Retainer, but rather an Air Eliminator, which appears to be a later modification of the original device.

However, I did find an earlier Illinois Heating Systems brochure online, and it goes into great detail and thoroughly describes your system. I have attached the PDF to this post. @Dan Holohan, You will probably want to put this into the Heating Museum too.

The Heat Retainer is a different configuration and design than the typical Air Eliminator device although it serves the same purpose. That being, to allow air to vent out, to prevent condensate from venting out, and to prevent air from reentering the system.

The first point of understanding with both the Return Trap and the Heat Retainer is to realize that the condensate return lines may run at different pressures than the boiler, depending on conditions. On considering the Return Trap and its function, one must first realize that at low boiler pressures of about 8 oz. or less, returning condensate will freely flow into the boiler without the aid of the Return Trap, thus, it will remain empty under most conditions. However, if boiler pressures rise above the 8 oz. level, the water level in the condensate return drop will "stack up" and because the Return Trap is vented through the Heat Retainer, condensate will back up into the Return Trap also. Remember that 1 psi is equal to a water column of about 28", meaning that for condensate to return unassisted from return lines that are at atmospheric pressure to a boiler that is at 1 PSI, the height of condensate backed up in the return piping would have to be greater than 28" above the water line in the boiler. Obviously, this becomes problematic at pressures greater than 8 oz. So, as pressure in the boiler rises above 8 oz., condensate will back up into the return trap. Boiler water will not flow into the return trap because of the swing check located between the Return Trap riser and the boiler. The Return Trap consists of a chamber in which there is a float valve. The Float simultaneously operates to valves at the top, one valve being a vent connection to the Heat Retainer and the other valve, a steam line connected to a Main. As the water rises to a point that the Return Trap is nearly filled, the float causes the vent port to suddenly close and at the same time, the steam port to open. This places the Return Trap at a pressure equal to the boiler. Flow from the Return Trap in a backward direction into the return lines is prevented by a second swing check. Since the Return Trap is now at a pressure equal to the boiler, the contents flow to the boiler and as the water level drops, the float causes the two valve ports to snap back to the original condition, that is, the steam port closes and the vent port opens. As long as the boiler pressure remains high enough, and condensate is flowing, the cycle will repeat itself. When boiler pressure falls, condensate will return by gravity to the boiler without the assistance of the Return Trap. If a system is regulated by a Vaporstat that is set at 8 oz, the Return Trap will never operate, but it is certainly a good backup device that will swing into action if the conditions warrant.

The Heat Retainer is a very interesting design, using a float, a chamber of water, and two connections to the condensate return piping. One connects below the boiler water line and the other to a high point and thus carries only air. In normal conditions, the float will be in a midway position and will cause the vent port to be open. This is the interesting point in the design in that the vent port is controlled by a dual acting valve instead of the typical single acting float valve plus and air check device as is found on most Air Eliminators. If pressure conditions cause a backup in the condensate return (which should not happen as long as the Return Trap is functioning correctly), the water level in the Heat Retainer will rise causing the float to close the vent port and prevent the release of condensate. If the fire dies down, or in the case of intermittent firing with gas or oil, the burner shuts off, a vacuum will start to form. The suction on the air vent line will cause the water in the device to migrate out of the chamber which contains the float, causing it to drop, which closes the vent port and prevents the reentry of air. As the system cools a vacuum will be formed throughout, as long as there are no leaks in valve stem packings, etc.

There has been considerable discussion in this forum regarding the desirability or undesirability of vacuum in a steam system. However, it is clear that vapor systems were intended to fall into a vacuum. After all, once you have the air out of the system, why would you want it to freely enter again when the boiler shuts off. Air blocks the flow of steam, but vacuum does not. When the boiler subsequently fires, the system will again vent air, but the amount of air is greatly reduced and the effort to expel it is greatly reduced, thus assisting the free flow of steam / vapor in an even manner throughout.

Dunham, Trane, and others went into much greater detail regarding vapor/vacuum operation and its desirability to ALL fuel types, and NOT just coal, as is often stated.

Since your Heat Retainer has view moving parts, if it were mine, I would first check it for proper operation if you can. If that is impossible during normal operation, I would wait until next summer. YOUR Heat Retainer has had a second vent added to the top. You might want to temporarily install a vent with greater capacity, such as a Gorton 2. Remember, the original design of the Heat Retainer offered no protection against the release of steam, because your crossover traps and radiator traps, if all working correctly, will never allow steam to get to the Heat Retainer. If you have bad traps, a vent like the Hoffman, which has been added would prevent its release. I wonder if someone has disabled the Heat Retainer and added a typical main vent instead of fixing a bad trap in your system. Just a thought.

I hope this helps with your understanding and does not add too much information..... and I hope my wordiness and thinking in circles is not confusing. HA!

PS. I have restored vacuum operation in my Dunham system and in very cold weather, vacuum levels as deep as 10" Hg will form. That's a whole lot of air that is not going in and out. It works great!!! Steam begins to flow to the radiators when the system is still in vacuum. Steam distribution is even and controllable. The system is nearly silent.

bmakenas

Much appreciated Dave!

I did manage to find that Illinois document as well, which was helpful. In addition, The Boiler Return Trap section within Dan's Lost Art of Steam Heating was helpful in the description of the boiler return trap and that it should not be confused for an F&T trap, which I assumed it was. In review of the Illinois piping diagram, it makes sense that the retainer and return trap could be dry if all things were operating properly. Condensate from the main supply returns would take the path of least resistance and drop into the wet return before entering into the retainer.

My only concern with the system at this point is that it seems to me that steam may not be moving through the radiators as quick as I would expect. And observing the air vent on the retainer, air isn't being exhausted as much as I would expect. Almost seems as if the air within the radiator return piping is not being relieved as it should, if that makes sense. Maybe I'm expecting too much....

For now I will plan to replace the air vent in the retainer with a Gorton 2 as well as plug/seal off the vacuum inlet port and see how things go.

Dave in QCA

I would not close any ports at all. On thin you might do I remove the Hoffman vent any run it open. It will tell you a lot. Do you feel more air? Do you get steam? I'm not sure which port you're callining the vacuum port? The original vent outlet? No need to close that.

bmakenas

I did pull the Dole air vent and put a square of toilet paper over the port. It moved slightly, but it remained over the port. I suppose I was expecting more exhausting, at least enough to push the paper off the port.

Vacuum port being the vacuum valve as indicated on the top of the heat retainer, page 11 of the Illinois document. Correct me if I'm wrong, but this device seems to be an air inlet of sorts. If I recall correctly, I believe the valve has an adjustable cover/cap that may open or close the valve.

Jamie Hall

As an aside... good Lord. I'm very glad I have a Hoffman Differential Loop, which seems to do the same thing with no moving parts!

bmakenas

Quick update on some progress.....

I removed the cap on the heat retainer original air check/vacuum valve and tried moving the piston. The piston was stuck so I lubricated it and was able to free it enough to slide up and down. This in itself opened the air passageway to the Dole air vent, which began whistling as I've never heard before. Evident with the whistling air was clearly being vented. While whistling I removed the Dole vent and the air vented out with even more force as anticipated, slightly blowing dust and particulate out from the retainer. Clearly there was restriction in air being relieved from the system. Steam moves much quicker through the mains and up to the dry return traps.

In addition I removed the radiator trap internals as recommended by Dave for a few of the radiators on the upper level and the kitchen. Steam moves to the radiators much faster and gets through most of the radiator now vs. only 1/2 or 2/3 as before. The radiator returns are not piping hot, therefore I believe the steam is condensing before it gets to the trap locations. It may be possible that the radiator valves have an orifice. Heat upstairs and in the kitchen has improved noticeably.

I also insulated the near boiler piping, which I suspect helped in some capacity. If anything it reduced the 90 degree plus boiler room temperature to below 80 degrees.

Lastly, I adjusted the swing on the thermostat so that there is a higher differential. This appears to help with not having the boiler kick on with a fraction of a degree drop, which would simply happen with someone walking past the thermostat. With this adjustment the boiler runs slightly longer as well in lieu of shutting off when it made up that fraction of a degree. I suspect this will be more efficient as well being the boiler doesn't shut off soon after steam is made, but not yet through the radiators.

I am getting some bouncing in the boiler sight glass, therefore I plan to skim sometime in the future. As well as replace the pigtail and add a low pressure gauge, being that I believe the existing pigtail is blocked. Original installation of the pigtail, vaporstat and gauge included a black iron pigtail and a combination of brass and black fittings and nipples. I suspect this combination has added to the interior crude condition.

Thanks for all who chimed in with suggestion and recommendations.

Dave in QCA

I'm glad you have made progress and that your system if performing better. It sounds like you're on the right track. Perhaps a project for next summer would be removal and tear down of the Heat Retainer, to clean it out and inspect, service, all parts. I suspect it is still not working perfectly. In proper operation, the Dole vent would be unnecessary. All venting comes through the piston valve. But, unless the piston is in the proper midway position, its not going to work right. I suspect there may be a clog in the lower passage between the two chambers.

However, there is still one thing that is confounding me. The proper operation of the Heat Retainer requires that is be full of water up to the level of the outlet. Yet, if it is dry, there is no way for the water to get into the this chamber. It is only connected to the air loop on the condensate returns. Rising pressure in the boiler, if it occurred would stack up water in the returns and cause the chamber to be filled, but without this, air passing through the chamber would eventually dry it out. If there is not water, the piston vent remains closed. Is this a design flaw? Is this the reason that they stopped producing the Heat Retainer and switched instead to an Air Eliminator of similar design of Dunham, Arco, and others? Very interesting.....

Dave in QCA

Found the source of Water!

Just went back to the system drawings and then looked and the very unique Illinois traps. Assuming that the outlets of the crossover traps connects to the horizontal inlet pipe at a point that is AFTER the connection of the pipe that allows condensate to drop down to the wet piping, and assuming that the original sideways Illinois traps are still in place, they would produce enough condensation from steam intermittently passed through the trap.

The Illinois System made a big deal about their trap design and the fact that the element is OUTSIDE of the steam, the opposite of all other thermostatic traps. Because of this, they claimed that their trap would allow complete heating of a radiator, where as other traps would close sooner and keep a portion of the radiator slightly cooler. In doing so, the Illinois trap will cool and reopen, even if steam is present, and sensing steam will immediately close. But, in this cycle, small amounts of steam will be emitted into the return piping for brief moment, enough perhaps to keep the Heat Retainer filled with water to the proper level.

bmakenas

Fortunately or unfortunately, the way the system is piped, primarily the fitting to the retainer from the main return (see pic), it is impractical for return condensate to enter into the retainer unless there was a significant volume of condensate within the returns, which there isn't. Return water will drop into the vertical before entering the retainer. The trap and retainer therefore are bone dry.

This condition is why I originally posted the consideration of eliminating the retainer and replacing with an air vent. I'm still not convinced it's helping the system in any positive way.....

Dave in QCA

What is that pipe that drops into the top of a Tee right to the left of the Retainer? It looks like it comes out of the end of the 2" pipe. what is that? Can you take another angle picture?

bmakenas

It's the 10 feet of 2" condenser pipe loop, per Illinois's piping diagram.

Dave in QCA

OK, I see that now. Very interesting! At what point does the outlet of the crossover traps connect. That is the traps that vent the ends of the steam mains. They should be connecting to this line somewhere in close proximity. Are they Illinois traps? Could you take a picture of them, close up if possible.

bmakenas

The crossover traps come in from the insulated pipe at the left of the retainer, pic 004 from above. The traps are within 6 feet or so of the retainer. The insulated pipe from the traps also combines with the radiator returns before the heat retainer/drop to the boiler return. The traps are Illinois 1G and have recently been rebuilt.

Dave in QCA

I am finally getting a clear picture of your entire system and also of the subtle nuances that are completely unique to this early version of the Illinois Vapor Heating System. I will try to address all of the issues that you have raised through the course of this thread.

First, you had mentioned that of your crossover traps, one got hot and the other remained cold. Your last post, you stated that they had recently been rebuilt. I assume they both get hot now. What method did you use to rebuild them? A cage unit, or original thermal disc replacement. Cage units tend to reduce the venting capacity. That being said, crossover traps are one of the best methods of venting your mains. They work just great. Your 1G traps vent at 0.86 cfm @ 8 oz. This is faster than a Hoffman 75 main vent, rated at 0.5 cfm. Compared to a cold Gorton #2, rated at 1.1 cfm, it is slower, but other than a cold start, your insulated mains are going to be warm, probably enough so to reduce the venting rate of a Gorton. In my experience on a similar system, a single crossover trap vastly outperforms a pair of Gorton #2s. Keep your crossover traps! They are great!

Relating to your heat retainer, I don't know how fast it can vent through the original two way piston valve, but I imagine it is adequate, and if fully operable, it would prevent the reentry of air when the boiler shuts off, thus reducing the amount of venting needed in subsequent cycles. This, of course, is dependent on the rest of the system being pretty tight, but I imagine you have serviced your radiator valves and have tightened packing nuts, etc. However, as you report, the Heat Retainer is dry and the unusual design of this device requires that it have a reservoir of water maintained in it. The source of replenishing that water is not from the system condensate, which drops down in the return piping about 1 foot before reaching the Heat Retainer, with all air from the system traveling into and through the Heat Retainer. The air flow would evaporate the reservoir of water if it is not replenished. The design is clear that new water would come from two sources. One is from the operation of the Return Trap. When it operates, it is filled with steam, the as the water drops away, the vent is reopened, allow residual steam to escape through a vent port, which leads into a condensing loop, which is pitched downward and connects to the air line just before it enters the Heat Retainer, which would then be carried into the Heat Retainer. The system drawings also clearly show that the outlets of the crossover trap are to be connected to the air line in a manner that any dribbles spit out of those vents would wind up in the Heat Retainer as well. However, in your system, the crossover traps are NOT connected as the drawing indicates. Given that the Return Trap will only operate when pressures rise to between 1 and 2 psi, and that may seldom, if ever happen in your system, unless you're coming out of a nighttime set back. This explains why your Heat Retainer is dry.

At the present time, there are short term improvements you could make, and also, some long term corrections. For short term, you need to improve your system venting because with no water, your piston valve is probably in the closed position, or nearly so. The Dole vent that has been added at sometime in the past, is also pretty slow. Now, realize that the piston vent valve offered no protection against steam, as none is needed as long as all of your radiator traps and your crossover traps are in working condition and do not allow steam to blow by. Protection against rising water is not needed because you have a working return trap. The Dole does not have a float and does not protect against water, and that does not appear to have ever caused a problem. As we have looked at this from all sides, you need an additional opening to let the air out, but do not need the functions of a main vent device that causes it to close in the presence of steam or rising water. You can accomplish this by simply removing the Dole vent. I do think I would install a pipe nipple to keep the threads clean and just so the vent point is clearly visible to you, a future owner, or a repair technician.

Under no circumstance would I remove the Heat Retainer. You have a high quality piece of ingenious engineering and a very rare, but completely intact piece of heating history. I sure wish all of the original pieces of my system were still present!

Open venting through the Heat Retainer gets your venting to where it needs to be. It causes no harm to the system. It leaves you the future option of doing a teardown and service of the Heat Retainer, combined with a piping correction, which would make your system completely operational, as it was a hundred years ago.

I'd really like to know how your system works as you move forward. Thank for posting this, because I have learned a lot about a system which I knew existed, but was totally unaware of the unusual design details. Where are you located? If in the Midwest, a stretch of cold weather is about a day away.

bmakenas

Thanks Dave.

Couple comments:
1) The crossover traps were rebuilt with the thermal discs. Both get hot relatively quickly now. One before the other, which is based on one supply main length being longer that the other.
2) Good to know how fast the 1G's vent. With this however, the system needs to purge this air as well, presumably just as quick for optimal operation. When manually moving the piston position up & down, the retainer air check does not seem to vent as much as the Dole vent. The Dole vent obviously can't keep up with the two 1G's venting capacity. I have purchased a Gorton 2 to replace the Dole, but have yet to install. Hopefully the Gorton 2 will vent adequately. If not I'll try leaving the retainer port open ended as you suggest.
3) Your right on the connection from the outlets of the crossover traps to the inlet side of the retainer. It is not piped exactly as the diagram however, would you anticipate that much drip from those to maintain the retainer water level? When I feel the outlet pipes from the crossover traps they are hot of course, but the closer you get towards the retainer, they are warm at best.
4) The main trap is bone dry as well as the retainer. Similar to the retainer, I'm unable to visualize how under normal low pressure system operating conditions, 8 oz. or so, that condensate could get into the main trap. If the way for the trap to fill with steam is via the small crossover connection between the steam main and trap, this doesn't appear to happen. The crossover is warm at best the further away from the steam main take-off. Room temperature before the trap. In addition, seems that unless the trap was under negative pressure, the steam wouldn't make it into the main trap from the crossover. For condensate to get into the main trap it seems it would need to come from the wet return main via the pipe drop at the bottom of the trap. This could only occur if the system operating pressure exceeds the head within the vertical rise between the boiler water level and the trap, which just doesn't happen.
5) The rest of the system is tight to the best of my knowledge. There are no leaks that I am aware of. The Illinois radiator valves are packless. They have not been rebuilt. Visuals of when system is operating does not expose any leaks at the valve stems, which can usually be seen if not heard in my limited experience.

At the end of the day the system has experienced improvements within the last couple weeks with the various tinkering. Hopefully some of which results in paying the gas man less.....

Dave in QCA

@bmakenas Regarding your list above:
#1. That seems just fine. Steam may not arrive at both crossovers at the same time, but it should balance out OK in operation. Your radiator inlet valves will provide some level of restriction and steam probably won't enter the radiator much or at all until both crossover traps close.
#2. Sounds great! Remember, if the Heat Retainer was working according to original design, there might be some inadequacy in the venting rate on a cold start up, but the piston valve will prevent air from returning to the system and the amount of air to be vented in subsequent cycles will be minimal and the piston valve should be able to handle it just fine.
#3. The fact that the outlet pipe from the crossover traps gets warm is an indicator that these traps allow a small amount of steam, and/or warm condensate to exit. It would not require much condensate to keep the Heat Reatainer filled, perhaps not more than a few dribbles now and then. These would have done the job. Too much flow would interfere with normal operation..
#4. The Return trap is normally dry. It does NOT need water in it to function. It will ONLY function under a condition when the boiler actually builds pressure to the point that gravity condensate return is stopped. One thing that may help you to visualize what happens, you might try marking the vertical pipe below the return trap with tape to indicate the elevation of the normal water line of the boiler. This will be the water line in this pipe as well. Then, place tape on the pipe at 14" intervals above the water line. At 8 oz of boiler pressure, return condensate will rise to 14" above the NWL, at 1 psi, 28", and so forth. Your measurements will show you just how much boiler pressure is required to cause the Return Trap to fill. When, it does fill, the float inside causes two valves to trip simultaneously. One valve closes the vent port and the other opens the steam port. The top of the Return Trap becomes filled with steam, equalizing the pressure of the Trap with that of the boiler, and then the condensate can flow by gravity downward and out of the Trap and into the boiler. But, as soon as the level in the trap is low enough to cause the float to drop far enough to cause the valves to trip back to the original position, the steam valve closes and the vent valve reopens, thus releasing the small quantity of pressurized steam into the condensing loop. If the boiler continues to fire, the Return Trap will continue to cycle, perhaps once per minute or so, thus returning the condensate. When pressure drops, normal gravity flow of condensate will be restored, and the Return Trap can rest until the next time that the boiler pressure rises. You describe your system that this seldom, if ever occurs. That is OK. When and IF your boiler pressure rises, for example, perhaps when coming out of a 15 degree setback that may have occurred during a power outage, your Return Trap will do its very critical job.

Great Job! Great system! Your crossover traps get your mains vented fast. Opening up the Heat Retainer with which ever method you decide upon will allow proper flow of the steam through the system. You should notice greatly improved comfort evenness, and reduced cost.

SteamCoffee

Dave, excellent explanation of what these things do! I have read much from Dunham, Ilinois, Hoffman etc., and this rocks. Seems that all this is overkill today as long as boiler pressure is kept reliably below designed pressures. Theses devices were vital when coal boilers ruled, draft regulators etc. worked pretty well, but not very fast! Later gas boiler pressures seems so much easier to regulate. Amazing to see one intact...thanks for the scholarship...

bmakenas

This past weekend I removed the old pigtail and installed a new brass one as well as a new low pressure gauge and the original code required pressure gauge. Also replaced the Dole vent with the Gorton 2 from the heat retainer.

System ran well after starting back up. Steam moved well through the mains. Boiler barely moved the pressure gauges. If I didn't know better, I would think it was running in a negative pressure. With outside temps around 15 and the boiler off for several hours, when I turned it back on I don't think it ever cracked an ounce of pressure. This was with the boiler firing for a couple hours non stop trying to make up the inside temperature loss. The radiator returns were warm after running some time. The only exception was the end of the west run with the radiator return from the kitchen radiator where I removed the radiator trap. This return was hot , evident of either steam passing through the radiator or just hot condensate due to the duration of time the system was running.

I took a closer look at the downstream side of the crossover trap piping arrangement and I believe I can divorce the pipe from the current return connection and re-pipe more direct to the retainer inlet side without too much trouble. I might wait to do this work during the non-heating season.

Dave what you indicate makes perfect sense with the main trap. Honestly, with the boiler cranking yesterday after being down for several hours and the boiler pressure barely cracking an ounce, I highly doubt water will ever enter the main trap unless I were to somehow increase the boiler pressure on my own. The boiler in place now is relatively compact in comparison to the original coal burning boiler and has a lower water level. I figure the boiler would need to be nearly 2 PSI before return water reached the trap.

Thanks again Dave!