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Help identifying my piping loop?...

Hey all,

So after all the wonderful recommendations here, I purchased "We got steam heat". Excellent and entertaining book!

I'm a bit confused on my setup however, and am curious about a few things.

I've enclosed two pictures, and commented on each.

1) There's a few obvious relief pipes, I dont understand.

2) I dont understand why my main goes out from east side of house, to the north of the house, no vents at all except at the radiators, then meets in the middle on the east side, same approx location as boiler, and returns, but also splits off to supply radiators on south side of house.

This return A, is the one on top that has the only main air vent.

Is it possible that steam goes out what I think is the Maine Return A, and they meet half way, and still condense back to the boiler. ie. is it possible steam is going up the one I labeled as main return B on the left?

Can condensate come back down the initial main and make it to the right on the header and down into the equalizer?

Does steam possibly go down the equalizer and across the close nipple then up the maine return B? I cant imagine this is possible, as everything below the fill line should be solid water, correct?

3) Would it be wise to add in a nipple/shutoff where I noted "Skimming Tap goes Here"?

4) Since it looks like I have an electric cutoff probe, is there anything in my setup that I should be leeching off a pint or so every now and then, or is this pretty much a closed system.

A few things I'm planning on doing.

1) Insulating all mains.

2) Putting an air vent almost in the middle of the east end where it branches off to second part of house.

3) Adding Skim valve.

4) Cleaning Low water probe (Exactly how do I do this?).

5) Adding a water meter at auto fill.

I have someone coming for the first cleaning in two years, so I want to be prepared for them, and have them install the vent and skim valve. And be prepared.

Since I have a Pressuretrol installed, there's no harm in a electronic thermostat, correct?

Thanks in advance all! Hopefully knuckleheads didn't install this. 8)


  • RodRod Posts: 2,067

    Hi -Unfortunately I can't seem to read your writing on the photos even when I blow them up.  If you could post the photos again without the labels, I can then add names and letters numbers which we can then ask you questions about.

    Probe- The LOW Water Cut OFF probe doesn't require anything but an annual inspection /cleaning which should be done by a pro. Bleeding off boiler water is done only on float type LWCO s  to make sure the float doesn't get clogged up with mud.

    Skim Tapping - It's a good idea to have a nipple and valve on the skim tapping so you can skim the boiler when necessary.  Also make sure that the valve has a plug or cap as an extra precaution against an accidental opening of the valve.

    The Pressuretrol just controls pressure. *the maximum pressure of your system should be no greater than 2 PSI and most systems run at less pressure. Lower pressure makes for better operation. Temperature is controlled by the thermostat. An electronic one will work okay.Just make sure that it has a function to be able to set cycles per hour. For steam this is usually 1 cycle per hour.

    Your description of your steam mains is a bit confusing. It might help  if you could draw out a plan view looking down on the piping from above.  Mark where the boiler and main vent(s) is located and also any drip pipes/ returns that drain condensate from the main. Also mark which way the pipe is sloped  with an arrow showing which way the (condensate) water flows.

    - Rod
  • CraigsCraigs Member Posts: 24
    Stay Tuned...

    Okay, more to come. Busy today though,. so not till tomorrow unless I can squeeze something in.

    I'll also draw up a diagram from above as described.

  • BobCBobC Member Posts: 4,409
    While your at it

    I agree with everything Rod has asked you to do and i would add a couple of things to his list. I'm assuming this is single pipe steam.

    Measure the length and pipe size of each main so we calculate the volume of air and then tell you what size main vents you need. Main vents are usually located after the last radiator takeoff on a single pipe steam system. Adequate main venting saves fuel and it makes the system heat more evenly.

    Use a level to check the pitch of each steam main, make sure the pitch does not change direction as the main runs along because this can trap water.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • RodRod Posts: 2,067
    Finding Pipe Sizes.

    Attached is a table which will help you determine the size of the pipes. Measure the circumference and then use the chart to find the pipe size.

    - Rod
  • CraigsCraigs Member Posts: 24
    More info

    Yes, single pipe.

    So I can figure out the pitch, that will take time, and is a task I will take on before insulating the mains.

    I've included a diagram of the house, although my drawing bites, cant even make straight lines.

    So the main thing I don't understand is why the main would go all throughout the house before returning and the vent is right before it reaches the boiler again. If I put on halfway down, wouldn't that help? Where the "Plug" is show in the picture. The pipe to the vent is a 1.5" pipe.

    Would a walk-through movie edited nicely to go through walls help? That I can do. Drawings, sub-par.

    Also, is that gauge I listed as pressure gauge, not actually a steam pressure gauge? I'm thinking this cause it goes from 0-30 PSI. Maybe a boiler tank guage for the hot water?
  • CraigsCraigs Member Posts: 24
    edited September 2013
    Bummer, photos still upload small.

    And I made those photos huge, with 36pt font.

    Forgot house layout. Hopefully this one is larger, it was only 51K in file size, but large in canvas size. Has almost no content, hence small file size.

    The arrows show the direction I "Believe" the steam is flowing. The only vent is right over the boiler, after the last radiator runs off the main.

    Radiators are on the end, and 1 means 1st floor, 2 is 2nd floor.

    Highlighted in Red is the loop and main line feed out. And dark black box is boiler of course.

    Also wanted to note. That pressure gauge on the front has never moved from a reading of '0' that I know of.

    Also. I put the photos in all their bigness at www dot somervillepost19 dot org/photos
  • RodRod Posts: 2,067
    One Pipe Steam System

    Hi- In your photos you have the wrong port labeled as the Skim Port. The Skim Port is the tapping immediately to the right of the top of the glass sight gauge. The tapping you have indicated as the Skim Port is used when you have a float type LWCO installed. Check your boiler I&O manual as there is a page which shows the different boiler tappings and what they are used for. If you don’t have a manual, let us know and we can post one for you.

    Pressure Gauge- The 0-30 PSI pressure gauge is required by code /insurance regs. Most people add a second gauge that reads lows pressures easier.

    Piping Diagram - From what I can see your main vent (s) are now in the proper location. Putting a main vent in the middle of the main is of little use. They should go at the end of the main after where the last radiator lateral is attached. If you measure your piping and give us a diagram of the size and lengths then, as Bob said, we can calculate how much venting you need and that can be added to the present location. The purpose of the main vent (s) is to rid the steam main of air as quickly as possible so that steam will reach all the radiator laterals at approximately the same time. Radiator vents are a different matter. If you vent them too quickly that can cause problems.

     The arrows in your diagram are rather confusing as the pitch of a radiator lateral (the pipe that joins the radiator to the main) is normally  counterflow and therefore  should slope from the radiator towards the main so that the condensate returns to the main. If the steam main is parallel flow then its highest point should be immediately above the boiler and its lowest point at the end of the return just before it drops down to meet the boiler. .

    Are you having problems with your system? If so, where and what problems are you having?

    I've attached a diagram of a typical single main one pipe system and a blurb on one pipe radiators which might be of help to you.

    - Rod
  • BobCBobC Member Posts: 4,409
    Might be ok if

    With a main like that it's important that it be sloped correctly so any condensate can easily find it's way back to the boiler. Piping can sag in an older home and there is always the possibility of knuckle heading over the years.  If the piping is all good having the vent where it is works just fine IF it's big enough, I can't tell for sure but that is a Ventrite 35 or Hoffman 4A it's probably too small to vent the mains quickly. The vent should be able to vent all the air out of a main in 3 minutes or less. Once you tell us the length and pipe size of your main we will know for sure.

    Does the system have any issues like water hammer? If it does you probably have water trapped in a main or a radiator because of slope issues.

    The 0-30 pressure gauge is not very useful at the pressures home heating boilers operate at (2PSI max) and gauges have been known to fail. Adding a 3PSI gauge would tell exactly where you are and can help ferret out venting issues.

    You want to add a skim port where that large plug is right above the junction box, small ports don't skim well. Getting that plug out may be a bear so be prepared for a fight.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • CraigsCraigs Member Posts: 24
    edited September 2013

    Thanks guys.

    So I don't have much of a problem, I'm just trying to get it working as efficiently, and quietly as possible.

    The header is 3"

    2" Mains

    1" Off the mains to radiators.

    Main run is (Minus the elbows) approx 39' Diagram in Photo 3.

    I had the unit serviced today. Added a pressure valve. He stated I should never touch the LWCO probe, and no need for skimming. Said to just take off rusty water from bottom drain once boiler is back in service this winter. (Which is against what others say about never adding new water, taking out old) Said I could do that as much as I wanted.

    Asked him to test the relief valve, said if he does, it most likely will need to be replaced, and it does it's thing, which I believe, and makes sense. If it's never used, why should it go bad, unless it rusts stuck.

    Vent is a VentRite No 35. Too small?

    In the diagram above, there are two sections of concern. One on the left, is pretty much level. So I could be getting pockets of water there, there is a bit of water hammer in the system I'd like to get rid of.

    The one in the first photo is a bummer, cause it actually dips down, maybe people at some time used it to hang stuff, or chin ups from, who knows, but it has a slight sag, and definitely goes a bit down them back up like a U, but not as severe of course. I took pictures. Second photo, it's pretty much level for that bit of the run, where everywhere else it pitches constant downward. All radiators are pitched and vented properly, new maid-o-mist with vent variance according to distance from boiler taken into consideration. (Love the way you can just spin out/in the vent sizes.

    What can be done about these dips? Floor jack underneath for a while, then a hanger, not sure.

    Also, in the service, the chamber was not opened and vacuumed out, should I do this, or leave it alone. He stuck the vacuum hose in the burner access hole and with on, then cleaned the flueways. Says this sucks down the soot, sediment, and it doesn't go airborne either. Guy was awesome, answered all my questions about the system I asked.

    So should I inspect/clean the probe type LWCO?

    Should I still install a skim tap?

    Can I safely run off rust in bottom of boiler come winter months? (Was suggested drain till clean).

    Should I get a larger main vent?
  • BobCBobC Member Posts: 4,409
    New vent and find a new plumber

    39 ft of 2" main is about 0.85 cu ft, you want that air out in a few minutes so I would replace that Ventrite #35 (0.11 CFM) with a Gorton #1 or a Maid O Mist #1 (both 0.33 cfm). If you had a low pressure gauge you could monitor the boiler as it comes up to steam to make sure the pressure is 0.25 PSI or less until the vent closes. If it gets higher you might need to add  a second vent.

    You should install a skim port in that large tapping just above the electric junction box, anybody that tells you not to is telling you they don't know as much as they think. Does the water in the sight glass bounce up and down much when making steam? If it does that boiler needs to be skimmed.  Probe type water level safeties should be inspected, it takes time and that is why people don't like to do it. To test it drain water out of the boiler and make sure the boiler cuts out when the water level gets to low - if the boiler does not shut off (about an inch below the bottom of the sight glass) the probe must be removed and inspected.

    Water in a steam boiler should be clean, you should drain till it runs clear and then turn the boiler on to make steam. You might want to wait for cold weather to do this, the water has to be brought up to a good boil to drive off the oxygen - that oxygen is why adding water is bad for a steam boiler. During the heating season draining off water is fine as long as you make steam right after adding the makeup water.

    The sag is a bit more difficult, how deep is the sag? Stretch some string along the main to judge the depth of the sag.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • CraigsCraigs Member Posts: 24
    Water in sight glass

    Does not bounce at all as far as I can recall.

    I'll grab a #1 Maid for my system.

    Checked with string, not enough sag to tell honestly, looks pretty straight actually. Just noticed originally with the 2' Level that it was not a level pitch there, and actually went back the other way for a bit it seemed, so figured it was a sag. Could just be crap on the pipe, will check more thoroughly later.

    So once boiler is cranking away this winter, it's fine to open up the drain and drain till clear? Should I crank heat up to 95 or so and wait for it to run say 5 mins then start draining, once I'm sure it's pushing steam out?

    Gauge for 0 to 3PSI is now installed. Some dual function that goes up to 3, then once over, will go from 10 - 30 PSI.

    Anybody have a recommended water feed meter that I can put in the loop before the auto feeder fairly inexpensive?
  • CraigsCraigs Member Posts: 24
    One Other things that was odd.

    Was that when the service person replaced the nozzle, he took out a .85 GPH, and replaced it with a .85GHP, but the specifications on the outside of the boiler/blower called for a 1.1GPH.

    What's the issue there, or is there an issue? Can I possibly get longer life out of the boiler overall since I'm putting in less fuel and it's working fine for hot water and steam?
  • CraigsCraigs Member Posts: 24
    edited September 2013
    Still Question remaining unanswered.

    Seems like once posts are no longer new, they get left in the dust.

    I provided answers to questions, and asked a few more questions, nut nothing in a few weeks. Guess the rest will remain a mystery.

    Remaining curiosities were:

    1) Sag isn't discernible, but there is still a bit of water hammer upon startup only. All radiators are pitched downward toward return. I always verify all vents at radiators are working. Nothing I can do for the slight sag? Will insulation help?

    2) Do I really need the skim tap if I have the probe type LWCO?

    3) Do I need to clean the LWCO probe, it says it's a self cleaning.

    4) So once boiler is cranking away this winter, it's fine to open up the drain and drain till clear? Should I crank heat up to 95 or so and wait for it to run say 5 mins then start draining, once I'm sure it's pushing steam out?

    5) Differences in Nozzle flow rates from above.

    6) Do I need to clean inner part of boiler? Service tech only put vacuum in the hole while cleaning from above, and said it was all that was needed.

This discussion has been closed.


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