2 pipe steam vapor system question
I recently moved into a house that has what I think is a 2 pipe steam vapor system. From what I have read on these forums I likely could benefit from more ventilation on my main steam line.
The vents on the main steam line look like what i see in pictures of other steam systems and i would replace them with 1 or more gorton #2 vents, but the return has an unusual vent or tap on it. In my system, the return line runs down and and through a check valve and connects to a return from the steam main, then runs to the boiler. So the steam and return both return condensate down to wet returns. This is repeated on two ends as the system has a W shape.
Two questions: what are the cents or taps at the end of the return and should these be left or replaced with updated vents (see pictures)? How many gorton #2s should be on each end of my steam mains if each leg is about 70 feet from the boiler, 20 feet of which is shared 2.5 inch and the other 50 feet on each leg consist of 2 inch pipe?
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The newer sections of black pipe and ball valves were recently added to allow me to flush and clean the return. The insides of the wet return were filled with "mud", but there was actually very little corrosion on the walls which was a nice surprise.
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I'm not sure what those crossover traps are doing unless those are dry returns unless they are just to ensure not steam gets in the return if there is enough of a pressure differential.
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The water line in the boiler is right around the level of that lowest horizontal pipe in the picture with the newer ball valve and union using a laser level. That is the farthest point from boiler (~20 feet) and the next set of returns is closer and lower. Not sure if that is helpful.
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I may have found the device by searching for the patent. It is patent number US1291099A for an air exhaust and vacuum seal valve. Agreed on the two valves. I had a situation in which the boiler pressure got too high and water sprayed out of them. Since cleaning the system (and insulating my house) that has not happened, but I need a vaporstat, as the pressures run below what my system can even control for (as I understand it). If I get a vapor stat, would I still need to raise these valves?
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Which is the main and which is the return here? I assume the vents are on the return since 2 pipe steam vents through the returns. Vents on the mains or crossover traps to allow the mains to vent in to the returns would help most likely. Larger vents would also help.
If it is some sort of known vapor system there may be some reason it needs to vent only on the returns.
Are there any special devices at the boiler? What is on the radiators? Are they standard valves or metering vapor valves? Are there traps on the radiators?
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The vents? Yes, I'd put them up at least 8 inches above the ells even if running at low pressure. Gets them away from any entrained crud.
Definitely do the vaporstat first to get the pressure under control. And an ounce gauge.
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.1 -
The radiators have a manual valve on the side steam enters and B&J 122 traps on the return. Vents, valves or devices near the boiler. I will say, besides one loud radiator upstairs, the system heats well, but takes a while to warm up.
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It certainly could be. Would a regular system's pressure still be below what my gauge and pressuretrol can register?
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I was afraid you were going to say that. Someone did you wrong, somewhere in the past. The boiler water level should be at least two feet above that horizontal pipe for every pound of pressure you run — so if you have a cutout of 8 ounces (typical vapour) it should be about 14 inches.
That's why the same bozo put in the check valves — which don't belong there — to keep the steam in the main from blowing back into the dry return. Which will stop your heat. Bad news. Check valves don't do that effectively.
There are ways to fix the problem… a false waterline is the easiest.
Those patented valves are a bit unusual, and they may — or may not — still work effectively. The idea is that they will let air out, but not steam. Are they working? Easy enough to figure out: when the boiler fires, the steam should get to them fairly quickly — and then stop. No steam coming out. If they aren't working properly, you can substitute a Gorton #2 on a short riser for them. Work just fine.
Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England2 -
Yes it looks like my cut in is set for 0.5 (all the way down) and the differential it at 1 or just below. It certainly was not able to cut off the boiler before water went out of my vents. So this is a regular two pipe system?
Back to the initial question - what do I do with those air/vacuum vents? Leave them, or do they get replaced by Gorton #2s as well?
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If they work (let out air but not steam) keep them. Replace the Hoffman and button vent above, they're bad.
Note @Jamie Hall 's comment about your check valves as well.
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.1 -
I wasn't sure if it was a steam trap or a check valve. a steam trap, if all of the drips were trapped would probably work although a false waterline or lowering the return would be better.
Old coal fired boilers typically had a waterline probably somewhere around 4 ft above the floor. Modern boilers have much lower waterlines so when the boiler was replaced piping that was supposed to be below the waterline to keep steam from moving from the supply to the return became above the waterline.
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Those big valves certainly seem to work. No steam and I can heard air come out of them after I did the work cleaning the return and fired up the boiler.
Bad news about the water level. I am going to double check my measure, but I don't think I was far off. Maybe the water is above the pipe by an inch, but not 14 inches. At the end of the wet return the pipe angles down significantly to take it closer to floor level, so there is slope to work with. Here is a picture once we are at the boiler. I will need to look up the structure, but is a false water line easier than trying to re-pipe the return?
EDIT: Confirmed that the first set of returns is above the boiler water line at its current fill level (second picture). The second of returns set is only 1 inch below.
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@chasvb . you're a lucky guy. This was originally an "O-E" Vapor system. You can find it in chapter 15 of @DanHolohan 's excellent book "The Lost Art of Steam Heating", available here:
Start with one Gorton #2 on each steam main, and add more if needed. You can leave the original O-E vents on the dry returns.
The B&J radiator traps were replacements. The original O-E radiator return fittings had little water seals in them, and small holes to let air through.
If the return lines bang where they run above the waterline, use a false water line at the boiler, as @Jamie Hall said. That shows up in Lost Art as well.
Where are you located?
All Steamed Up, Inc.
Towson, MD, USA
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Consulting3 -
Thanks for more information about the system. This is turning into a pretty interesting rabbit hole. The system performs very well overall. Totally quiet besides a single upstairs radiator and it is very clear that it is the pipe in which the steam rises causing the issues, and only for about 20 seconds when the boiler first fires. I'm pretty sure it is not insulated and it is against a (likely) uninsulated single wythe brick wall, so maybe steam condensing as it rises? Upside is the 100 year old bricks look brand new as they never freeze.
If the system is working, can I opt to put new valves on the steam mains and leave the rest of the system alone for another year?
I'm located in the Chicago area.
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Yes, you can. If you're in Chicagoland, @The Steam Whisperer is your guy for vapor.
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.1 -
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Thanks for tips on the local expert. That will certainly come in handy.
Also thanks for guidance on banging in the line. I do wonder if the supply line has a short horizontal run under the floor before the radiator. If this was not sloped would that cause banging? I replaced the capsule in the steam trap on that radiator this season with a Tunstall capsule, but it didn't change much.
The additive is 8-way. Water will be drained and rinsed, but yes while I boiled it with the additive, it was moving a half inch or so up and down. I've been trying to clean up what I don't think had been drained more than a couple of times in the 15 years since the boiler was installed. I decided to risk an impact wrench to remove the 1.5 inch plug to add a skim port. Honestly it flew right out.
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In my observations, 1/2” of movement is not surging, it’s just boiling. Water looks very clean in photo
NJ Steam Homeowner.
Free NJ and remote steam advice: https://heatinghelp.com/find-a-contractor/detail/new-jersey-steam-help/
See my sight glass boiler videos: https://bit.ly/3sZW1el2 -
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then do all you can to limit the amount of fresh water added. Measure the ph with some test strips from Amazon and shoot for 11 ph.
NJ Steam Homeowner.
Free NJ and remote steam advice: https://heatinghelp.com/find-a-contractor/detail/new-jersey-steam-help/
See my sight glass boiler videos: https://bit.ly/3sZW1el1 -
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This.
All Steamed Up, Inc.
Towson, MD, USA
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Consulting0
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